Patent Publication Number: US-2023157678-A1

Title: Systems and Methods for Lead Delivery

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 63/283,103, filed Nov. 24, 2021 and to U.S. Provisional Patent Application No. 63/395,281, filed Aug. 4, 2022. The disclosures of each are incorporated herein by reference in their entirety. 
    
    
     DESCRIPTION OF THE RELATED ART 
     Electrical leads can be implanted in patients for a variety of medical purposes. In one particular application, leads can be implanted to work in conjunction with a cardiac pacemaker or cardiac defibrillator. Pacemakers and cardiac defibrillators are medical devices that help control abnormal heart rhythms. A pacemaker uses electrical pulses to prompt the heart to beat at a normal rate. The pacemaker may speed up a slow heart rhythm, control a fast heart rhythm, and/or coordinate the chambers of the heart. Defibrillators can be provided in patients who are expected to, or have a history of, severe cardiac problems that may require electrical therapies up to and including the ceasing of ventricular fibrillation, otherwise known as cardiac arrest. Defibrillators may include leads that are physically inserted into the heart, including into the heart tissue (e.g., with screw-in lead tips) for the direct delivery of electrical current to the heart muscle. 
     The portions of pacemaker or ICD systems generally comprise three main components: a pulse generator, one or more wires called leads, and electrode(s) found on each lead. The pulse generator produces the electrical signals that help regulate the heartbeat. Most pulse generators also have the capability to receive and respond to signals that come from the heart. Leads are generally flexible wires that conduct electrical signals from the pulse generator toward the heart. One end of the lead is attached to the pulse generator and the other end of the lead, containing the electrode(s) is positioned on, in or near the heart. 
     While many of the exemplary embodiments discussed herein refer to cardiac pacing, it is contemplated that such embodiments and technologies disclosed may also be used in conjunction with defibrillation/ICD applications. Similarly, when exemplary embodiments discussed herein refer to defibrillation/ICD applications, it is contemplated that the embodiments and technologies disclosed may also be used in conjunction with cardiac pacing applications. 
     SUMMARY 
     In one aspect, a method is disclosed that includes inserting an insertion dilator into an insertion sheath such that the insertion dilator extends out from a distal end of an insertion sheath, penetrating patient skin with the insertion dilator to push the insertion sheath through the skin to reach a particular depth, removing the insertion dilator from the insertion sheath, inserting a delivery system into the insertion sheath, and deploying a lead by advancing the lead through an insertion tip of the delivery system. 
     In a related aspect, an insertion sheath is disclosed that is configured to receive a delivery system and facilitate positioning of an insertion tip of the delivery system within a patient, the insertion tip including a window through which a lead can be loaded. The insertion sheath includes an insertion sheath body having a hollow interior shaped to receive the delivery system, an insertion sheath hub extending laterally from the insertion sheath body at a proximal end of the insertion sheath, and an insertion sheath stopping foot extending laterally from the insertion sheath body. 
     In some variations, the insertion sheath and the insertion sheath stopping foot can be configured to result in the insertion tip being positioned at a particular depth within the patient. The insertion sheath is further configured to decrease a size of the window. 
     In other variations, the insertion sheath hub can include a valve configured to close around the delivery system to reduce air exchange through the hollow interior of the insertion sheath. 
     In yet other variations, the insertion sheath can include a separable portion that is at least partially separable along at least a portion of a length of the insertion sheath. 
     In a related aspect, an insertion dilator is configured to separate patient tissue and to be used with an insertion sheath, the insertion dilator including: an insertion dilator body having a handle, an insertion dilator stopping foot extending laterally and configured to engage the insertion sheath, and having a length such that a portion of the insertion dilator body extends beyond the insertion sheath and a pointed end configured to separate the patient tissue. 
     In some variations, the insertion dilator can include a puncture tip configured to extend distally from the pointed end of the insertion dilator. The insertion dilator can be configured to cause advancement of the puncture tip up to a predefined amount from the pointed end of the insertion dilator. 
     In some variations, the insertion dilator can include a button that causes advancement of the puncture tip from the pointed end of the insertion dilator and the button can be recessed into the handle of the insertion dilator. 
     In other variations, the puncture tip can be retractable into the insertion dilator and the insertion dilator can include a spring-actuated retraction mechanism can have a spring operatively connected to the puncture tip and configured to retract the puncture tip into the insertion dilator. 
     In yet other variations, the insertion dilator can be configured for exchangeable ends. 
     In a related aspect, a kit includes a delivery system with an insertion tip configured to be loaded with a lead through a window, the delivery system further configured to deploy the lead through the insertion tip. The kit includes an insertion sheath configured to receive the delivery system and facilitate positioning of the insertion tip of the delivery system within a patient, the insertion sheath having an insertion sheath body having a hollow interior shaped to receive the delivery system, an insertion sheath hub extending laterally from the insertion sheath body at a proximal end of the insertion sheath, and an insertion sheath stopping foot extending laterally from the insertion sheath body. The kit also includes an insertion dilator configured to separate patient tissue and to be used with the insertion sheath, the insertion dilator having an insertion dilator body having a handle, an insertion dilator stopping foot extending laterally and configured to engage the insertion sheath, and having a length such that a portion of the insertion dilator body extends beyond the insertion sheath and a pointed end configured to separate the patient tissue. 
     In some variations, the kit can include an anchor cap having an aperture with a shape corresponding to a cross-section of a proximal part of the lead over which the anchor cap is configured to be placed. The anchor cap can have a cap body and a cap head that extends laterally beyond the cap body, with one or more holes or notches on the cap head to facilitate suturing to patient tissue and/or to the lead. 
     In a related aspect, a system includes a delivery system having an insertion tip configured to be loaded with a lead, the delivery system configured to deploy the lead through a distal opening in an insertion tip and a dilator cap configured to fit over the insertion tip and cover the distal opening in the insertion tip. 
     In some variations, the dilator cap can include a tissue-separating portion that is wedge-shaped. The dilator cap can include a shoulder configured to engage the delivery system for advancing the dilator cap. The dilator cap can be shaped to compliment a shape of the delivery system to engage the delivery system for advancing the dilator cap. 
     Also disclosed in detail herein are numerous implementations of lead designs, electrode designs, delivery systems, delivery system accessories to facilitate implementation, systems for securing leads to a patient, electrical stimulation control systems, software and sensors to work with control systems, etc. 
     Implementations of the current subject matter can include, but are not limited to, methods consistent with the descriptions provided herein as well as articles that comprise a tangibly embodied machine-readable medium operable to cause one or more machines (e.g., computers, etc.) to result in operations implementing one or more of the described features. Similarly, computer systems are also contemplated that may include one or more processors and one or more memories coupled to the one or more processors. A memory, which can include a computer-readable storage medium, may include, encode, store, or the like, one or more programs that cause one or more processors to perform one or more of the operations described herein. Computer implemented methods consistent with one or more implementations of the current subject matter can be implemented by one or more data processors residing in a single computing system or across multiple computing systems. Such multiple computing systems can be connected and can exchange data and/or commands or other instructions or the like via one or more connections, including but not limited to a connection over a network (e.g., the internet, a wireless wide area network, a local area network, a wide area network, a wired network, or the like), via a direct connection between one or more of the multiple computing systems, etc. 
     The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. While certain features of the currently disclosed subject matter are described for illustrative purposes in relation to particular implementations, it should be readily understood that such features are not intended to be limiting. The claims that follow this disclosure are intended to define the scope of the protected subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawings, 
         FIG.  1    is a diagram illustrating exemplary placements of elements of a cardiac pacing system, in accordance with certain aspects of the present disclosure; 
         FIG.  2 A  is an illustration of an exemplary lead delivery system facilitating delivery of a cardiac pacing lead in the region of a cardiac notch, in accordance with certain aspects of the present disclosure; 
         FIG.  2 B  illustrates a distal end of an exemplary lead delivery system having dropped into an intercostal space in the region of the cardiac notch, in accordance with certain aspects of the present disclosure; 
         FIG.  2 C  illustrates an electrical lead exiting the exemplary delivery system with two electrodes positioned on a side of the lead facing the heart, in accordance with certain aspects of the present disclosure; 
         FIG.  3    illustrates an exemplary delivery system, in accordance with certain aspects of the disclosure; 
         FIG.  4    illustrates an example of first and second insertion tips of the delivery system with blunt edges, in accordance with certain aspects of the disclosure; 
         FIG.  5    illustrates an exemplary channel at least partially complimentary to a shape of the component and configured to guide the component into the patient, in accordance with certain aspects of the disclosure; 
         FIG.  6    illustrates a first insertion tip being longer than a second insertion tip, in accordance with certain aspects of the disclosure; 
         FIG.  7    illustrates an example of a ramped portion of an insertion tip, in accordance with certain aspects of the disclosure; 
         FIG.  8    illustrates an example of insertion tips with open side walls, in accordance with certain aspects of the disclosure; 
         FIG.  9 A  illustrates one possible example of a delivery system having a unitary insertion tip, in accordance with certain aspects of the disclosure; 
         FIG.  9 B  illustrates one possible example of a unitary insertion tip, in accordance with certain aspects of the disclosure; 
         FIG.  9 C  illustrates an alternative insertion tip design having a wedge shape, in accordance with certain aspects of the disclosure; 
         FIG.  9 D  illustrates certain features applicable to a unitary insertion tip design, in accordance with certain aspects of the disclosure; 
         FIG.  10    illustrates an exemplary lock for a delivery system, in a locked position, in accordance with certain aspects of the disclosure; 
         FIG.  11    illustrates the lock in an unlocked position, in accordance with certain aspects of the disclosure; 
         FIG.  12 A  illustrates an example rack and pinion system that may be included in a component advancer of the delivery system, in accordance with certain aspects of the disclosure; 
         FIG.  12 B  illustrates an example clamp system that may be included in a component advancer of the delivery system, in accordance with certain aspects of the disclosure; 
         FIG.  13    illustrates a view of an exemplary implementation of a component advancer including a pusher tube coupled with the handle of a delivery system, in accordance with certain aspects of the disclosure; 
         FIG.  14    illustrates another view of the exemplary implementation of the component advancer including the pusher tube coupled with the handle of the delivery system, in accordance with certain aspects of the disclosure; 
         FIG.  15    illustrates the exemplary insertion tips in an open position, in accordance with certain aspects of the disclosure; 
         FIG.  16    illustrates an example implementation of an electrical lead, in accordance with certain aspects of the disclosure; 
         FIG.  17    illustrates another example implementation of an electrical lead, in accordance with certain aspects of the disclosure; 
         FIG.  18    illustrates a distal portion of an exemplary electrical lead bent in a predetermined direction, in accordance with certain aspects of the disclosure; 
         FIG.  19    illustrates the distal portion bending in the predetermined direction when the lead exits the delivery system, in accordance with certain aspects of the disclosure; 
         FIG.  20 A  illustrates an exemplary implementation of the distal portion of a lead, in accordance with certain aspects of the disclosure; 
         FIG.  20 B  illustrates another exemplary implementation of the distal portion of a lead, in accordance with certain aspects of the disclosure, in accordance with certain aspects of the disclosure; 
         FIG.  21 A  is a simplified diagram illustrating an exemplary junction box in accordance with certain aspects of the present disclosure; 
         FIG.  21 B  is a flow chart illustrating an exemplary process for performing defibrillation in accordance with certain aspects of the disclosure; 
         FIG.  22    illustrates an example of an electrode, in accordance with certain aspects of the disclosure; 
         FIG.  23    illustrates a cross section of the example electrode, in accordance with certain aspects of the disclosure; 
         FIG.  24    is a diagram illustrating a simplified perspective view of an exemplary directional lead with panel electrodes in accordance with certain aspects of the present disclosure; 
         FIG.  25 A  is a diagram illustrating a simplified perspective view of an exemplary directional lead with elliptical panel electrodes in accordance with certain aspects of the present disclosure; 
         FIG.  25 B  is a diagram illustrating a simplified perspective view of an exemplary directional lead with elliptical coil electrodes in accordance with certain aspects of the present disclosure; 
         FIG.  26    is a diagram illustrating a simplified perspective view of an exemplary directional lead with embedded directional electrodes in accordance with certain aspects of the present disclosure; 
         FIG.  27    is a diagram illustrating a simplified perspective view of an exemplary directional lead with masked circumferential defibrillation coil electrodes in accordance with certain aspects of the present disclosure; 
         FIG.  28    is a diagram illustrating a simplified perspective view of an exemplary directional lead with embedded directional electrodes in accordance with certain aspects of the present disclosure; 
         FIG.  29    is a diagram illustrating a simplified perspective view of an exemplary directional lead with masked circumferential defibrillation coil electrodes in accordance with certain aspects of the present disclosure; 
         FIGS.  30 A and  30 B  illustrate an exemplary splitting lead exiting a delivery system, in accordance with certain aspects of the present disclosure; 
         FIGS.  31 A and  31 B  illustrate exemplary implantation locations/orientations for exemplary splitting leads, in accordance with certain aspects of the present disclosure; 
         FIG.  32    illustrates an exemplary splitting lead exiting an exemplary delivery system, in accordance with certain aspects of the present disclosure; 
         FIG.  33    illustrates an exemplary splitting lead with wrapped electrodes, in accordance with certain aspects of the present disclosure; 
         FIG.  34    illustrates an exemplary splitting lead with an electrode extension, in accordance with certain aspects of the present disclosure; 
         FIG.  35    illustrates an exemplary embodiment of a splitting lead that includes a protective collar for an electrode on an electrode extension, in accordance with certain aspects of the present disclosure; 
         FIG.  36    illustrates an exemplary splitting lead with an embedded circular helical coil electrode, in accordance with certain aspects of the present disclosure; 
         FIG.  37    illustrates an exemplary splitting lead with an embedded elliptical helical coil electrode, in accordance with certain aspects of the present disclosure; 
         FIG.  38    illustrates an exemplary splitting lead with multiple embedded electrodes, in accordance with certain aspects of the present disclosure; 
         FIG.  39    illustrates an exemplary splitting lead with multiple side-by-side embedded electrodes, in accordance with certain aspects of the present disclosure; 
         FIG.  40 A  illustrates an exemplary splitting lead with offset embedded electrodes, in accordance with certain aspects of the present disclosure; 
         FIG.  40 B  illustrates an exemplary splitting lead with offset embedded electrodes that fit into opposing concavities, in accordance with certain aspects of the present disclosure; 
         FIG.  41 A  illustrates an exemplary delivery system deploying a component, in accordance with certain aspects of the present disclosure; 
         FIG.  41 B  illustrates the delivery system of  FIG.  41 A  at a later stage of deployment, in accordance with certain aspects of the present disclosure; 
         FIG.  41 C  illustrates the delivery system of  FIG.  41 A  at a yet later stage of deployment, in accordance with certain aspects of the present disclosure; 
         FIG.  41 D  illustrates an exemplary gap-filling component of a splitting lead for use with a delivery system such as depicted in  FIGS.  41 A-C , in accordance with certain aspects of the present disclosure; 
         FIG.  42    illustrates exemplary components of a delivery system configured to load (or reload) a component (e.g., an electrical lead) into the delivery system, in accordance with certain aspects of the disclosure; 
         FIG.  43    illustrates an example of an alignment block coupled to a proximal portion of an electrical lead, in accordance with certain aspects of the disclosure; 
         FIG.  44 A  illustrates an exemplary insertion dilator and insertion sheath, in accordance with certain aspects of the disclosure; 
         FIGS.  44 B and  44 C  illustrate an exemplary use and structure of a puncture tip for an insertion dilator, in accordance with certain aspects of the disclosure; 
         FIG.  44 D  illustrates an exemplary recessed button for the insertion dilator, in accordance with certain aspects of the disclosure; 
         FIG.  44 E  illustrates a delivery system with an exemplary dilator cap, in accordance with certain aspects of the disclosure; 
         FIG.  45    illustrates removal of the insertion dilator from the insertion sheath, in accordance with certain aspects of the disclosure; 
         FIG.  46    illustrates exemplary features of a lead delivery system that facilitate loading a splitting lead into the insertion tip of the system, in accordance with certain aspects of the disclosure; 
         FIG.  47 A  illustrates utilization of a delivery system having an insertion tip that is inserted into an insertion sheath, in accordance with certain aspects of the disclosure; 
         FIG.  47 B  illustrates exemplary embodiments of insertion sheaths, in accordance with certain aspects of the disclosure; 
         FIG.  48    illustrates deployment of a splitting lead, in accordance with certain aspects of the disclosure; 
         FIG.  49    illustrates the insertion sheath creating a reduced window size that improves deployment of the splitting lead, in accordance with certain aspects of the disclosure; 
         FIG.  50    illustrates removal of the delivery system and insertion tip, in accordance with certain aspects of the disclosure; 
         FIGS.  51 - 53    illustrate removal of an insertion sheath embodiment having separating portions, in accordance with certain aspects of the disclosure; 
         FIG.  54    illustrates a lead with exemplary suture holes, in accordance with certain aspects of the present disclosure; 
         FIG.  55    illustrates an exemplary lead anchor for securing a lead, in accordance with certain aspects of the present disclosure; 
         FIGS.  56 A- 56 D  illustrate exemplary lead anchor insertion systems and methods for pushing a lead anchor onto a lead, in accordance with certain aspects of the present disclosure; 
         FIG.  57 A  illustrates an exemplary lead with indentations for securing the lead to tissue, in accordance with certain aspects of the present disclosure; and 
         FIG.  57 B  illustrates an exemplary lead and anchor cap, in accordance with certain aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Implantable medical devices such as cardiac pacemakers or implantable cardioverter defibrillators (ICDs) may provide therapeutic electrical stimulation to the heart of a patient. The electrical stimulation may be delivered in the form of electrical pulses or shocks for pacing, cardioversion or defibrillation. This electrical stimulation is typically delivered via electrodes on one or more implantable leads that are positioned in, on or near the heart. The concepts described herein can be applied to leads that include pacing and/or defibrillation electrodes unless otherwise specifically stated. 
     In one particular implementation discussed herein, a lead may be inserted in the region of the cardiac notch of a patient so that the distal end of the lead is positioned within the mediastinum, adjacent to the heart. For example, the distal end of the lead may be positioned in the anterior mediastinum, beneath the patient&#39;s sternum. The distal end of the lead can also be positioned so to be aligned with an intercostal space in the region of the cardiac notch. Other similar placements in the region of the cardiac notch, adjacent the heart, are also contemplated for this particular application of cardiac pacing. 
     In one exemplary procedure, as shown in  FIG.  1   , a cardiac pacing lead  100  may be inserted within the ribcage  101  of a patient  104  through an intercostal space  108  in the region of the cardiac notch. Lead  100  may be inserted through an incision  106 , for example. The incision  106  may be made in proximity to the sternal margin to increase the effectiveness in finding the appropriate intercostal space  108  and avoiding certain anatomical features, for example the lung  109 . The incision may be made lateral to the sternal margin, adjacent the sternal margin or any other direction that facilitates access to an appropriate intercostal space  108 . A distal end of lead  100  can be positioned to terminate within the mediastinum of the thoracic cavity of the patient, proximate the heart  118 . Lead  100  may then be connected to a pulse generator or controller  102 , which may be placed above the patient&#39;s sternum  110 . In alternative procedures, for temporary pacing, a separate controller may be used that is not implanted in the patient. 
     In some implementations, the pericardium is not invaded by the lead during or after implantation. In other implementations, incidental contact with the pericardium may occur, but heart  118  (contained within the pericardium) may remain untouched. In still further procedures, epicardial leads, or leads that reside within the pericardium, which do invade the pericardium, may be inserted. 
       FIG.  2 A  is an illustration of an exemplary lead delivery system  200  facilitating delivery of a lead in the region of a cardiac notch.  FIG.  2 A  illustrates delivery system  200  and a cross section  201  (including left chest  203  and right chest  207 ) of a patient  104 .  FIG.  2 A  illustrates sternum  110 , lung  109 , intercostal muscle  108 , heart  118 , mediastinum  202 , pericardium  204 , and other anatomical features. As shown in  FIG.  2 A , lead delivery system  200  may be configured to allow for a distal end  206  of delivery system  200  to be pressed against the sternum  110  of patient  104 . 
     In one implementation, a physician identifies an insertion point above or adjacent to a patient&#39;s sternum  110  and makes an incision. The distal end  206  of delivery system  200  can then be inserted through the incision, until making contact with sternum  110 . The physician can then slide distal end  206  of delivery system  200  across sternum  110  toward the sternal margin until it drops through the intercostal muscle  108  in the region of the cardiac notch under pressure applied to the delivery system  200  by the physician.  FIG.  2 B  illustrates the distal end  206  having dropped through the intercostal muscle in the region of the cardiac notch toward the pericardium. 
     In certain implementations, delivery system  200  may include an orientation or level guide  316  to aid the physician with obtaining the proper orientation and/or angle of delivery system  200  to the patient. Tilting delivery system  200  to the improper angle may negatively affect the deployment angle of lead  100  into the patient. For example, a horizontal level guide  316  on delivery system  200  helps to ensure that the physician keeps delivery system  200  level with the patient&#39;s sternum thereby ensuring lead  100  is delivered at the desired angle. 
     Following this placement of delivery system  200 , the system may be actuated to insert an electrical lead  100  into the patient.  FIG.  2 C  illustrates an exemplary electrical lead  100  exiting delivery system  200  with two electrodes  210 ,  212  positioned on one side of lead  100 , within the mediastinum  202  and facing heart  118 .  FIG.  2 C  illustrates the lead  100  advancing in a direction away from sternum  110 . This example is not intended to be limiting. For example, the lead  100  may also be advanced in a direction parallel to the sternum  110 . In some implementations, delivery system  200  may be configured such that lead  100  advances in the opposite direction, under sternum  110 , advances away from sternum  110  at an angle that corresponds to an angle of one or more ribs of patient  104 , and/or advances in other orientations. Similarly, an exemplary device as shown in  FIG.  2    may be flipped around so that the handle would be on the left side of  FIG.  2   , or held in other positions by the physician, prior to system actuation and insertion of lead  100 . 
     Distal end  206  of delivery system  200  may be configured to move or puncture tissue during insertion, for example, with a relatively blunt tip (e.g., as described herein), to facilitate entry into the mediastinum without requiring a surgical incision to penetrate through intercostal muscles and other tissues. A blunt access tip, while providing the ability to push through tissue, can be configured to limit the potential for damage to the pericardium or other critical tissues or vessels that the tip may contact. 
     In an exemplary implementation, the original incision made by the physician above or adjacent to the sternum may also be used to insert a controller, pulse generator or additional electrode to which the implanted lead may be connected. 
     The delivery system and lead technologies described herein may be especially well suited for the cardiac pacing lead delivery example described above. While this particular application has been described in detail, and may be utilized throughout the descriptions below, it is contemplated that the delivery system(s)  200  and lead(s)  100  herein may be utilized in other procedures as well, such as the insertion of a defibrillation lead. 
       FIG.  3    illustrates an exemplary delivery system  200 . Delivery system  200  can include a handle  300 , a component advancer  302 , a first insertion tip  304 , a second insertion tip  306 , a lock  308 , and/or other components. Handle  300  may be configured to be actuated by an operator. In some implementations, handle  300  may be coupled to a body  310  and/or other components of delivery system  200 . Body  310  may include an orifice  312 , finger depressions  314 , a knurled surface, a lever arm, and/or other components configured to facilitate gripping of handle  300  by an operator. In some implementations, handle  300  and the body of the delivery system  200  may be coated with a material or their surfaces covered with a texture to prevent slippage of the physician&#39;s grasp when using delivery system  200 . 
     Component advancer  302  may be coupled to handle  300  and configured to advance a component such as an electrical lead (as one example) into the patient by applying a force to the portion of the component in response to actuation of handle  300  by the operator. 
     First insertion tip  304  and second insertion tip  306  may be configured to close around a distal tip and/or segment of the component when the component is placed within component advancer  302 . In some implementations, closing around a distal segment of the component may include blocking a path between the component and the environment outside delivery system  200 . Closing around the distal segment of the component may also prevent the component from being unintentionally deployed and contacting biological tissue while delivery system  200  is being manipulated by the operator. 
     First insertion tip  304  and second insertion tip  306  may also be configured to fully enclose the distal segment of the component when the component is placed within component advancer  302 . Fully enclosing the distal segment of the component may include covering, surrounding, enveloping, and/or otherwise preventing contact between the distal segment of the component and an environment around first insertion tip  304  and second insertion tip  306 . 
     In still other implementations, first insertion tip  304  and second insertion tip  306  may be configured to only partially enclose the distal segment of the component when the component is placed within component advancer  302 . For example, first insertion tip  304  and/or second insertion tip  306  may cover, surround, envelop, and/or otherwise prevent contact between one or more portions (e.g., surfaces, ends, edges, etc.) of the distal segment of the component and the environment around tips  304  and  306 , but the tips  304  and  306  may also still block the path between the component and the environment outside the delivery system  200  during insertion. 
     In some implementations, first insertion tip  304  and second insertion tip  306  may be configured such that the component is held within component advancer  302  rather than within first insertion tip  304  and second insertion tip  306 , prior to the component being advanced into the patient. 
     First insertion tip  304  and second insertion tip  306  may be further configured to push through biological tissue when in a closed position and to open (see, e.g.,  320  in  FIG.  3   ) to enable the component to exit from the component advancer  302  into the patient. In some implementations, opening may comprise second insertion tip  306  moving away from first insertion tip  304 , and/or other opening operations. In some implementations, first and second insertion tips  304 ,  306  may be configured to open responsive to actuation of handle  300 . 
     In some implementations, first insertion tip  304  and/or second insertion tip  306  may be configured to close (or re-close) after the component exits from the component advancer  302 , to facilitate withdrawal of delivery system  200  from the patient. Thus, first insertion tip  304  and second insertion tip  306  may be configured to move, after the component exits from component advancer  302  into the patient, to a withdrawal position to facilitate withdrawal of first insertion tip  304  and second insertion tip  306  from the biological tissue. In some implementations, the withdrawal position may be similar to and/or the same as an original closed position. In some implementations, the withdrawal position may be a different position. In some implementations, the withdrawal position may be wider than the closed position, but narrower than an open position. For example, first insertion tip  304  and/or second insertion tip  306  may move to the open position to release the component, but then move to a different position with a narrower profile (e.g., the withdrawal position) so that when the tips  304 ,  306  are removed they are not met with resistance pulling through a narrow rib space, and/or other biological tissue. 
     In some implementations, first and second insertion tips  304 ,  306  may have blunt edges. Blunt edges may include rounded and/or otherwise dull edges, corners, surfaces, and/or other components of first and second insertion tips  304 ,  306 . The blunt edges may be configured to prevent insertion tips  304  and  306  from rupturing any veins or arteries, the pericardial sac, the pleura of the lungs, and/or causing any other unintentional damage to biological tissue. The blunt edges may prevent, for example, rupturing veins and/or arteries by pushing these vascular items to the side during insertion. The blunt edges may also prevent, for example, the rupturing of the pericardium or pleura because they are not sharp. 
       FIG.  4    illustrates first and second insertion tips  304 ,  306  with exemplary implementations of such blunt edges. As shown in  FIG.  4   , first and second insertion tips  304 ,  306  may have rounded corners  400 ,  402  and/or end surfaces  401 ,  403  at their respective ends  404 ,  406 . First and second insertion tips  304 ,  306  may have rounded edges  408 ,  410  that run along a longitudinal axis of tips  304 ,  306 . However, this description is not intended to be limiting. In some implementations, first and second insertion tips  304 ,  306  may also have sharp edges, ends, and/or other features. 
     In some implementations, first and second insertion tips  304 ,  306  may each include a channel at least partially complimentary to a shape of the component and configured to guide the component into the patient.  FIG.  5    illustrates an example of such a channel. As shown in  FIG.  5   , first insertion tip  304  may include a channel  500  at least partially complimentary to a shape of the component and configured to guide the component into the patient. Second insertion tip  306  may also include a channel similar to and/or the same as channel  500  (although the channel in insertion tip  306  is not visible in  FIG.  5   ). Channel  500  may extend along a longitudinal axis of insertion tip  304  from an end  502  of insertion tip  304  configured to couple with component advancer  302  toward end  404 . 
     In some implementations, channel  500  may be formed by a hollow area of insertion tip  304  that forms a trench, for example. The hollow area and/or trench may have one or more shapes and/or dimensions that are at least partially complimentary to a shape and/or dimension(s) of the component, and are configured to guide the component into the patient. In some implementations, the hollow area and/or trench may be configured such that the component may only slide within channel  500  inside the insertion tips  304 ,  306 , and therefore prevent the component from advancing out one of the sides of the insertion tips  304 ,  306  when pushed by component advancer  302 . 
     In some implementations, channel  500  may include a second channel and/or groove configured to engage alignment features included on a component. The second channel or groove may be located within channel  500 , but be deeper and/or narrower than channel  500 . The component may then include a rib and/or other alignment features configured to engage such a groove. The rib may be on an opposite side of the component relative to electrodes, for example. These features may enhance the guidance of a component through channel  500 , facilitate alignment of a component in channel  500  (e.g., such that the electrodes are oriented in a specific direction in tips  304 ,  306 , preventing the component from exiting tips  304 ,  306  to one side or the other (as opposed to exiting out ends  404 ,  406 ), and/or have other functionalities. 
     In some implementations, the second channel and/or groove may be sized to be just large enough to fit an alignment feature of the component within the second channel and/or groove. This may prevent an operator from pulling a component too far up into delivery system  200  ( FIG.  3   ) when loading delivery system  200  with a component (e.g., as described below). 
     The channels and/or grooves may also provide a clinical benefit. For example, the channel and/or groove may allow for narrower insertion tips  304  and  306  that need not be configured to surround or envelop all sides of the component (e.g., they may not need sidewalls to keep the component in position during implantation). If surrounding or enveloping all sides of a component is necessary, the insertion tips would need to be larger, and would meet with greater resistance when separating tissue planes within intercostal spaces, for example. However, in other implementations (e.g., as described herein), insertion tips  304 ,  306  may completely surround and/or envelop the component. 
     In some implementations, as shown in  FIG.  6   , a first insertion tip  304  may be longer than a second insertion tip  306  and the end  404  of first insertion tip  304  will extend beyond the end  406  of insertion tip  306 . Such a configuration may assist with spreading of tissue planes and help to avoid pinching tissue, veins, arteries or the like while delivery system  200  is being manipulated through biological tissue. 
     In some implementations, both the first and second insertion tips  304 ,  306  may be moveable. In other implementations, the first insertion tip  304  may be fixed, and second insertion tip  306  may be moveable. 
     In one particular implementation, a fixed insertion tip  304  may be longer than a movable insertion tip  306 . This configuration may allow more pressure to be exerted on the outermost edge (e.g., end  404  of tip  304 ) of delivery system  200  without (or with reduced) concern that tips  304  and  306  will open when pushing through biological tissue. Additionally, the distal ends  404  and  406  may form an underbite  600  that allows distal end  406  of movable insertion tip  306  (in this example) to seat behind fixed insertion tip  304 , and thus prevent tip  406  from experiencing forces that may inadvertently open movable insertion tip  306  during advancement. However, this description is not intended to be limiting. In some implementations, a movable insertion tip  306  may be longer than a fixed insertion tip  304 . 
     In some implementations, a fixed (e.g., and/or longer) insertion tip  304  may include a ramped portion configured to facilitate advancement of the component into the patient in a particular direction.  FIG.  7    illustrates an example of a ramped portion  700  of insertion tip  304 . Ramped portion  700  may be located on an interior surface  702  of insertion tip  304 , between channel  500  and distal end  404  of insertion tip  304 . Ramped portion  700  may be configured to facilitate advancement of the component into the patient in a particular direction. The particular direction may be a lateral direction relative to a position of insertion tip  304 , for example. The lateral deployment of a component (e.g., an electrical lead) when it exits insertion tip  304  and moves into the anterior mediastinum of the patient may facilitate deployment without contacting the heart (e.g., as described relative to  FIGS.  2 A- 2 C  above). Ramped portion  700  may also encourage the component to follow a preformed bias (described below) and help prevent the lead from deploying in an unintentional direction. 
     In some implementations, insertion tips  304 ,  306  may have open side walls.  FIG.  8    illustrates an example of insertion tips  304 ,  306  with open side walls  800 ,  802 .  FIG.  8    illustrates a cross sectional view of insertion tips  304 ,  306 , looking at insertion tips  304 ,  306  from distal ends  404 ,  406  (as shown in  FIG.  7   ). Open side walls  800 ,  802  may be formed by spaces between insertion tip  304  and insertion tip  306 . In the example of  FIG.  8   , insertion tips  304  and  306  are substantially “U” shaped, with the ends  804 ,  806 ,  808 ,  810  extending toward each other, but not touching, such that open side walls  800  and  802  may be formed. Open side walls  800 ,  802  may facilitate the use of a larger component (e.g., a component that does not fit within channel(s)  500 ), without having to increase a size (e.g., a width, etc.) of insertion tips  304 ,  306 . This may avoid effects larger insertion tips may have on biological tissue. For example, larger insertion tips are more invasive than smaller insertion tips. As such, larger insertion tips may meet with greater resistance when separating tissue planes within intercostal spaces during deployment and may cause increased trauma than insertion tips having a reduced cross sectional size. 
     In some implementations, delivery system  200  ( FIG.  3   ) may include a handle  300  ( FIG.  3   ), a component advancer  302  ( FIG.  3   ), and a unitary insertion tip (e.g., instead of first and second insertion tips  304  and  306 ).  FIG.  9 A  illustrates one possible example of a delivery system  200  having a unitary insertion tip  900 . Insertion tip  900  may be coupled to a component advancer  302  similar to and/or in the same manner that insertion tips  304  and  306  ( FIG.  7   ) may be coupled to component advancer  302 . 
     Unitary insertion tip  900  may have a circular, rectangular, wedge, square, and/or other cross sectional shape(s). In some implementations, insertion tip  900  may form a (circular or rectangular, etc.) tube extending along a longitudinal axis  902  ( FIG.  9 B ) of insertion tip  900 . Referring to  FIG.  9 B , in some implementations, insertion tip  900  may be configured to hold the component (labeled as  904 ) when the component is placed within component advancer  302 . In some implementations, insertion tip  900  may be configured to hold a distal end (labeled as  906 ) and/or tip of component  904  when component  904  is placed within component advancer  302 . 
     Insertion tip  900  may be configured to push through biological tissue and may include a distal orifice  908  configured to enable component  904  to exit from component advancer  302  into the patient. 
       FIG.  9 C  illustrates an alternative insertion tip  900  design having a wedge shape. A wedge-shaped insertion tip  900  reduces and/or eliminates the exposure of distal orifice  908  to the surrounding tissue during insertion. This design prevents tissue coring since only the leading edge of insertion tip  900  is exposed and thereby separates tissues rather than coring or cutting tissue during insertion. Accordingly, the present disclosure contemplates an insertion tip that may be configured to reduce the exposure of the distal orifice during insertion. 
     Referring to  FIG.  9 D , distal tip  912  may be rounded into an arc so the deployment force exerted by the physician during insertion concentrates in a smaller area (the distalmost portion of distal tip  912 ). Additionally, the distalmost portion of distal tip  912  may be blunted to minimize trauma and damage to surrounding tissue during insertion. Notch  914  provides additional room for the proximal end of lead  100  having a rigid electrical connector to more easily be inserted when loading lead  100  in delivery system  200 . Rails  916  overlap lead  100  and hold lead  100  flat when the lead is retracted and held within delivery system  200 . In some implementations, the inner edge of rails  916  gradually widen as rails  916  advance toward distal tip  912 . 
       FIG.  9 D  illustrates certain features applicable to a unitary insertion tip design. 
     In some implementations, insertion tip  900  may include a movable cover  918  configured to prevent the biological tissue from entering distal orifice  908  when insertion tip  900  pushes through the biological tissue. The moveable cover may move to facilitate advancement of component  904  into the patient. 
     It is contemplated that many of the other technologies disclosed herein can also be used with the unitary tip design. For example, insertion tip  900  may include a ramped portion  910  configured to facilitate advancement of the component into the patient in a particular direction and to allow the protruding electrodes  210 ,  212  to pass easier through the channel created within insertion tip  900 . 
     In some implementations, delivery system  200  ( FIG.  3   ) may include a dilator. In some implementations, insertion tips  304 ,  306 , and/or insertion tip  900  may operate in conjunction with such a dilator. Use of a dilator may allow an initial incision to be smaller than it may otherwise be. The dilator may be directionally oriented to facilitate insertion of a component (e.g., an electrical lead) through the positioned dilator manually, and/or by other means. The dilator may comprise a mechanism that separates first and second insertion tips  304 ,  306 . For example, relatively thin first and second insertion tips  304 ,  306  may be advanced through biological tissue. An actuator (e.g., a handle, and/or a device couple to the handle operated by the user) may insert a hollow, dilating wedge that separates first and second insertion tips  304 ,  306 . The actuator (operated by the user) may advance a lead through the hollow dilator into the biological tissue. The dilator may also be used to separate the first and second insertion tips  304 ,  306  such that they lock into an open position. The dilator can then be removed and the lead advanced into the biological tissue. 
       FIGS.  10  and  11    illustrate an exemplary lock  1000  that may be included in delivery system  200 . A lock  1000  may be similar to and/or the same as lock  308  shown in  FIG.  3   . In some implementations, lock  1000  may be configured to be moved between an unlocked position that allows actuation of handle  300  (and in turn component advancer  302 ) by the operator and a locked position that prevents actuation, and prevents first insertion tip  304  ( FIG.  7   ) and second insertion  306  tip ( FIG.  7   ) from opening. 
       FIG.  10    illustrates lock  1000  in a locked position  1002 .  FIG.  11    illustrates lock  1000  in an unlocked position  1004 . Lock  1000  may be coupled to handle  300  and/or component advancer  302  via a hinge  1003  and/or other coupling mechanisms. In some implementations, lock  1000  may be moved from locked position  1002  to unlocked position  1004 , and vice versa, by rotating and/or otherwise moving an end  1006  of lock  1000  away from handle  300  (see, e.g.,  1005  in  FIG.  11   ). Lock  1000  may be moved from locked position  1002  to unlocked position  1004 , and vice versa, by the operator with thumb pressure, trigger activation (button/lever, etc.) for example, and/or other movements. Additionally, the mechanism may also include a safety switch such that a trigger mechanism must be deployed prior to unlocking the lock with the operator&#39;s thumb. 
     When lock  1000  is engaged or in locked position  1002 , lock  1000  may prevent an operator from inadvertently squeezing handle  300  to deploy the component. Lock  1000  may prevent the (1) spreading of the distal tips  304 ,  306 , and/or (2) deployment of a component while delivery system  200  is being inserted through the intercostal muscles. 
     Lock  1000  may be configured such that deployment of the component may occur only when lock  1000  is disengaged (e.g., in the unlocked position  1004  shown in  FIG.  11   ). Deployment may be prevented, for example, while an operator is using insertion tips  304 ,  306  of delivery system  200  to slide between planes of tissue in the intercostal space as pressure is applied to delivery system  200 . Lock  1000  may be configured such that, only once system  200  is fully inserted into the patient can lock  1000  be moved so that handle  300  may be actuated to deliver the component through the spread (e.g., open) insertion tips  304 ,  306 . It should be noted that the specific design of lock  1000  shown in  FIGS.  10  and  11    is not intended to be limiting. Other locking mechanism designs are contemplated. For example, the lock  1000  may be designed so that lock  1000  must be fully unlocked to allow the handle  300  to be deployed. A partial unlocking of lock  1000  maintains the handle in the locked position as a safety mechanism. Furthermore, the lock  1000  may be configured such that any movement from its fully unlocked position will relock the handle  300 . 
     Returning to  FIG.  3   , component advancer  302  may be configured to advance a component into a patient. The component may be an electrical lead (e.g., as described herein), and/or other components. 
     The component advancer  302  may be configured to removably engage a portion of the component, and/or to deliver the component into the patient through insertion tips  304  and  306 . In some implementations, component advancer  302  and/or other components of system  200  may include leveraging components configured to provide a mechanical advantage or a mechanical disadvantage to an operator such that actuation of handle  300  by the operator makes advancing the component into the patient easier or more difficult. For example, the leveraging components may be configured such that a small and/or relatively light actuation pressure on handle  300  causes a large movement of a component (e.g., full deployment) from component advancer  302 . Or, in contrast, the leveraging components may be configured such that a strong and/or relatively intense actuation pressure is required to deliver the component. In some implementations, the leveraging components may include levers, hinges, wedges, gears, and/or other leveraging components (e.g., as described herein). In some implementations, handle  300  may be advanced in order to build up torque onto component advancer  302 , without moving the component. Once sufficient torque has built up within the component advancer, the mechanism triggers the release of the stored torque onto the component advancer, deploying the component. 
     In some implementations, component advancer  302  may include a rack and pinion system coupled to handle  300  and configured to grip the component such that actuation of handle  300  by the operator causes movement of the component via the rack and pinion system to advance the component into the patient. In some implementations, the rack and pinion system may be configured such that movement of handle  300  moves a single or dual rack including gears configured to engage and rotate a single pinion or multiple pinions that engage the component, so that when the single pinion or multiple pinions rotate, force is exerted on the component to advance the component into the patient. 
       FIG.  12 A  illustrates an exemplary rack and pinion system  1200 . Rack and pinion system may include rack(s)  1202  with gears  1204 . Example system  1200  includes two pinions  1206 ,  1208 . Pinions  1206  and  1208  may be configured to couple with a component  1210  (e.g., an electrical lead), at or near a distal end  1212  of component  1210 , as shown in  FIG.  12 A . Rack and pinion system  1200  may be configured such that movement of handle  300  moves rack  1202  comprising gears  1204  configured to engage and rotate pinions  1206 ,  1208  that engage component  1210 , so that when pinions  1206 ,  1208  rotate  1214 , force is exerted  1216  on component  1210  to advance component  1210  into the patient. 
     In some implementations, responsive to handle  300  being actuated, a component (e.g., component  1210 ) may be gripped around a length of a body of the component, as shown in  FIG.  12 B . The body of the component may be gripped by two opposing portions  1250 ,  1252  of component advancer  302  that engage either side of the component, by two opposing portions that engage around an entire circumferential length of a portion of the body, and/or by other gripping mechanisms. 
     Once gripped, further actuation of handle  300  may force the two opposing portions within component advancer  302  to traverse toward a patient through delivery system  200 . Because the component may be secured by these two opposing portions, the component may be pushed out of delivery system  200  and into the (e.g., anterior mediastinum) of the patient. By way of a non-limiting example, component advancer  302  may comprise a clamp  1248  having a first side  1250  and a second side  1252  configured to engage a portion of the component. Clamp  1248  may be coupled to handle  300  such that actuation of handle  300  by the operator may cause movement of the first side  1250  and second side  1252  of clamp  1248  to push on the portion of the component to advance the component into the patient. Upon advancing the component a fixed distance (e.g., distance  1254 ) into the patient, clamp  1248  may release the component. Other gripping mechanisms are also contemplated. 
     Returning to  FIG.  3   , in some implementations, component advancer  302  may include a pusher tube coupled with handle  300  such that actuation of handle  300  by the operator causes movement of the pusher tube to push on the portion of the component to advance the component into the patient. In some implementations, the pusher tube may be a hypo tube, and/or other tubes. In some implementations, the hypo tube may be stainless steel and/or be formed from other materials. However, these examples are not intended to be limiting. The pusher tube may be any tube that allows system  200  to function as described herein. 
       FIGS.  13  and  14    illustrate different views of an exemplary implementation of a component advancer  302  including a pusher tube  1300  coupled with handle  300 . As shown in  FIG.  13   , in some implementations, pusher tube  1300  may include a notch  1302  having a shape complementary to a portion of a component and configured to maintain the component in a particular orientation so as to avoid rotation of the component within system  200 .  FIG.  13    shows notch  1302  formed in a distal end  1304  of pusher tube  1300  configured to mate and/or otherwise engage with an end of a distal portion of a component (not shown in  FIG.  13   ) to be implanted. Pusher tube  1300  may be configured to push, advance, and/or otherwise propel a component toward and/or into a patient via notch  1302  responsive to actuation of handle  300 . 
     In some implementations, the proximal end  1308  of pusher tube  1300  may be coupled to handle  300  via a joint  1310 . Joint  1310  may be configured to translate articulation of handle  300  by an operator into movement of pusher tube  1300  toward a patient. Joint  1310  may include one or more of a pin, an orifice, a hinge, and/or other components. In some implementations, component advancer  302  may include one or more guide components  1314  configured to guide pusher tube  1300  toward the patient responsive to the motion translation by joint  1310 . In some implementations, guide components  1314  may include sleeves, clamps, clips, elbow shaped guide components, and/or other guide components. Guide components  1314  may also add a tensioning feature to ensure the proper tactile feedback to the physician during deployment. For example, if there is too much resistance through guide components  1314 , then the handle  300  will be too difficult to move. Additionally, if there is too little resistance through the guide components  1314 , then the handle  300  will have little tension and may depress freely to some degree when delivery system  200  is inverted. 
       FIG.  14    provides an enlarged view of distal end  1304  of pusher tube  1300 . As shown in  FIG.  14   , notch  1302  is configured with a rectangular shape. This rectangular shape is configured to mate with and/or otherwise engage a corresponding rectangular portion of a component (e.g., as described below). The rectangular shape is configured to maintain the component in a specific orientation. For example, responsive to a component engaging pusher tube  1300  via notch  1302 , opposing (e.g., parallel in this example) surfaces, and/or the perpendicular (in this example) end surface of the rectangular shape of notch  1302  may be configured to prevent rotation of the component. This notch shape is not intended to be limiting. Notch  1302  may have any shape that allows it to engage a corresponding portion of a component and prevent rotation of the component as described herein. For example, in some implementations, pusher tube  1300  may include one or more coupling features (e.g., in addition to or instead of the notch) configured to engage the portion of the component and configured to maintain the component in a particular orientation so as to avoid rotation of the component within system  200 . These coupling features may include, for example, mechanical pins on either side of the pusher tube  1300  configured to mate with and/or otherwise engage receptacle features on a corresponding portion of a component. 
       FIG.  15    illustrates insertion tips  304  and  306  in an open position  1502 .  FIG.  15    also illustrates pusher tube  1300  in an advanced position  1500 , caused by actuation of handle  300  (not shown). Advanced position  1500  of pusher tube  1300  may be a position that is closer to insertion tips  304 ,  306  relative to the position of pusher tube  1300  shown in  FIG.  14   . 
     In some implementations, the component advancer  302  may include a wedge  1506  configured to move insertion tip  304  and/or  306  to the open position  1502 . In some implementations, wedge  1506  may be configured to cause movement of the moveable insertion tip  306  and may or may not cause movement of insertion tip  304 . 
     Wedge  1506  may be coupled to handle  300 , for example, via a joint  1510  and/or other components. Joint  1510  may be configured to translate articulation of handle  300  by an operator into movement of the wedge  1506 . Joint  1510  may include one or more of a pin, an orifice, a hinge, and/or other components. Wedge  1506  may be designed to include an elongated portion  1507  configured to extend from joint  1510  toward insertion tip  306 . In some implementations, wedge  1506  may include a protrusion  1509  and/or other components configured to interact with corresponding parts  1511  of component advancer  302  to limit a travel distance of wedge  1506  toward insertion tip  306  and/or handle  300 . 
     Wedge  1506  may also be slidably engaged with a portion  1512  of moveable insertion tip  306  such that actuation of handle  300  causes wedge  1506  to slide across portion  1512  of moveable insertion tip  306  in order to move moveable insertion tip  306  away from fixed insertion tip  304 . For example, insertion tip  306  may be coupled to component advancer  302  via a hinge  1520 . Wedge  1506  sliding across portion  1512  of moveable insertion tip  306  may cause moveable insertion tip to rotate about hinge  1520  to move moveable insertion tip  306  away from fixed insertion tip  304  and into open position  1502 . In some implementations, moveable insertion tip  306  may be biased to a closed position. For example, a spring mechanism  1350  (also labeled in  FIGS.  13  and  14   ) and/or other mechanisms may perform such biasing for insertion tip  306 . Spring mechanism  1350  may force insertion tip  306  into the closed position until wedge  1506  is advanced across portion  1512 , thereby separating insertion tip  306  from insertion tip  304 . 
     In some implementations, as described above, first insertion tip  304  and second insertion tip  306  may be moveable. In some implementations, first insertion tip  304  and/or second insertion tip  306  may be biased to a closed position. For example, a spring mechanism similar to and/or the same as spring mechanism  1350  and/or other mechanisms may perform such biasing for first insertion tip  304  and/or second insertion tip  306 . In such implementations, system  200  may comprise one or more wedges similar to and/or the same as wedge  1506  configured to cause movement of first and second insertion tips  304 ,  306 . The one or more wedges may be coupled to handle  300  and slidably engaged with first and second insertion tips  304 ,  306  such that actuation of handle  300  may cause the one or more wedges to slide across one or more portions of first and second insertion tips  304 ,  306  to move first and second insertion tips  304 ,  306  away from each other. 
     In some implementations, system  200  may comprise a spring/lock mechanism or a rack and pinion system configured to engage and cause movement of moveable insertion tip  306 . The spring/lock mechanism or the rack and pinion system may be configured to move moveable insertion tip  306  away from fixed insertion tip  304 , for example. A spring lock design may include design elements that force the separation of insertion tips  304  and  306 . One such example may include spring forces that remain locked in a compressed state until the component advancer or separating wedge activate a release trigger, thereby releasing the compressed spring force onto insertion tip  306 , creating a separating force. These spring forces must be of sufficient magnitude to create the desired separation of tips  304  and  306  in the biological tissue. Alternatively, the spring compression may forceable close the insertion tips until the closing force is released by the actuator. Once released, the tips are then driven to a separating position by the advancement wedge mechanism, as described herein. 
     In some implementations, the component delivered by delivery system  200  (e.g., described above) may be an electrical lead for implantation in the patient. The lead may comprise a distal portion, one or more electrodes, a proximal portion, and/or other components. The distal portion may be configured to engage component advancer  302  of delivery system  200  (e.g., via notch  1302  shown in  FIGS.  13  and  14   ). The distal portion may comprise the one or more electrodes. For example, the one or more electrodes may be coupled to the distal portion. The one or more electrodes may be configured to generate therapeutic energy for biological tissue of the patient. The therapeutic energy may be, for example, electrical pulses and/or other therapeutic energy. The biological tissue may be the heart (e.g., heart  118  shown in  FIG.  1   - FIG.  2 C ) and/or other biological tissue. The proximal portion may be coupled to the distal portion. The proximal portion may be configured to engage a controller when the lead is implanted in the patient. The controller may be configured to cause the one or more electrodes to generate the therapeutic energy, and/or perform other operations. 
       FIG.  16    illustrates an example implementation of an electrical lead  1600 . Lead  1600  may comprise a distal portion  1602 , one or more electrodes  1604 , a proximal portion  1606 , and/or other components. Distal portion  1602  may be configured to engage component advancer  302  of delivery system  200  (e.g., via notch  1302  shown in  FIGS.  13  and  14   ). In some implementations, distal portion  1602  may comprise a proximal shoulder  1608 . Proximal shoulder may be configured to engage component advancer  302  (e.g., via notch  1302  shown in  FIGS.  13  and  14   ) such that lead  1600  is maintained in a particular orientation when lead  1600  is advanced into the patient. For example, in some implementations, proximal shoulder  1608  may comprise a flat surface  1610  (e.g., at a proximal end of distal portion  1602 ). In some implementations, proximal shoulder  1608  may comprise a rectangular shape  1612 . Flat surface  1610  and/or rectangular shape  1612  may be configured to correspond to a (e.g., rectangular) shape of notch  1302  shown in  FIGS.  13  and  14   . In some implementations, transition surfaces between flat surface  1610  and other portions of distal portion  1602  may be chamfered, rounded, tapered, and/or have other shapes. 
     In some implementations, proximal shoulder  1608  may include one or more coupling features configured to engage component advancer  302  to maintain the lead in a particular orientation so as to avoid rotation of the lead when the lead is advanced into the patient. In some implementations, these coupling features may include receptacles for pins included in pusher tube  1300 , clips, clamps, sockets, and/or other coupling features. 
     In some implementations, proximal shoulder  1608  may comprise the same material used for other portions of distal portion  1602 . In some implementations, proximal shoulder may comprise a more rigid material, and the material may become less rigid across proximal shoulder  1608  toward distal end  1620  of distal portion  1602 . 
     In some implementations, proximal shoulder  1608  may function as a fixation feature configured to make removal of lead  1600  from a patient (and/or notch  1302 ) more difficult. For example, when lead  1600  is deployed into the patient, lead  1600  may enter the patient led by a distal end  1620  of the distal portion  1602 . However, retracting lead  1600  from the patient may require the retraction to overcome the flat and/or rectangular profile of flat surface  1610  and/or rectangular shape  1612 , which should be met with more resistance. In some implementations, delivery system  200  ( FIG.  3   ) may include a removal device comprising a sheath with a tapered proximal end that can be inserted over lead  1600  so that when it is desirable to intentionally remove lead  1600 , the flat and/or rectangular profile of shoulder  1608  does not interact with the tissue on the way out. 
       FIG.  17    illustrates another example implementation  1700  of electrical lead  1600 . In some implementations, as shown in  FIG.  17   , distal portion  1602  may include one or more alignment features  1702  configured to engage delivery system  200  ( FIG.  3   ) in a specific orientation. For example, alignment features  1702  of lead  1600  may include a rib  1704  and/or other alignment features configured to engage a groove in a channel (e.g., channel  500  shown in  FIG.  5   ) of insertion tip  304  and/or  306  ( FIG.  5   ). Rib  1704  may be on an opposite side  1706  of the lead  1600  relative to a side  1708  with electrodes  1604 , for example. These features may enhance the guidance of lead  1600  through channel  500 , facilitate alignment of lead  1600  in channel  500  (e.g., such that electrodes  1604  are oriented in a specific direction in tips  304 ,  306 ), prevent lead  1600  from exiting tips  304 ,  306  to one side or the other (as opposed to exiting out ends  404 ,  406  shown in  FIG.  4   ), and/or have other functionality. 
     In some implementations, rib  1704  may be sized to be just large enough to fit within the groove in the channel  500 . This may prevent the lead from moving within the closed insertion tips  304 ,  306  while the insertion tips are pushed through the intercostal muscle tissue. Additionally, rib  1704  may prevent an operator from pulling lead  1600  too far up into delivery system  200  ( FIG.  3   ) when loading delivery system  200  with a lead (e.g., as described below). This may provide a clinical benefit, as described above, and/or have other advantages. 
       FIG.  18    illustrates distal portion  1602  of lead  1600  bent  1800  in a predetermined direction  1804 . In some implementations, distal portion  1602  may be pre-formed to bend in predetermined direction  1804 . The pre-forming may shape set distal portion  1602  with a specific shape, for example. In the example, shown in  FIG.  18   , the specific shape may form an acute angle  1802  between ends  1620 ,  1608  of distal portion  1602 . The pre-forming may occur before lead  1600  is loaded into delivery system  200  ( FIG.  3   ), for example. In some implementations, distal portion  1602  may comprise a shape memory material configured to bend in predetermined direction  1804  when lead  1600  exits delivery system  200 . The shape memory material may comprise nitinol, a shape memory polymer, and/or other shape memory materials, for example. The preforming may include shape setting the shape memory material in the specific shape before lead  1600  is loaded into delivery system  200 . 
     Distal portion  1602  may be configured to move in an opposite direction  1806 , from a first position  1808  to a second position  1810  when lead  1600  enters the patient. In some implementations, first position  1808  may comprise an acute angle  1802  shape. In some implementations, the first position may comprise a ninety degree angle  1802  shape, or an obtuse angle  1802  shape. In some implementations, the second position may comprise a ninety degree angle  1802  shape, or an obtuse angle  1802  shape. Distal portion  1602  may be configured to move from first position  1808  to second position  1810  responsive to the shape memory material being heated to body temperature or by removal of an internal wire stylet, for example. In some implementations, this movement may cause an electrode side of distal portion  1602  to push electrodes  1604  into tissues toward a patient&#39;s heart, rather than retract away from such tissue and the heart. This may enhance electrical connectivity and/or accurately delivering therapeutic energy toward the patient&#39;s heart, for example. 
       FIG.  19    illustrates distal portion  1602  bending  1800  in the predetermined direction  1804  when lead  1600  exits delivery system  200 . In some implementations, as shown in  FIG.  19   , the predetermined direction may comprise a lateral and/or transverse direction  1900  relative to an orientation  1902  of insertion tips  304  and/or  306 , a sternum of the patient, and/or other reference points in delivery system  200  and/or in the patient. 
     Any of the designs discussed herein can have a predetermined shape that can result in a lead moving in a predetermined direction or having a predetermined shape when the lead exits delivery system  200 . In some cases, the direction can be determined or facilitated by the design of the delivery system (e.g., implementations herein where leads are directed utilizing ramps). In other implementations, the direction or shape may be determined by the design of the lead itself (e.g., a lead with a preformed shape that is forced to be held straight when within delivery system  200  but that assumes the preformed shape again upon exiting the delivery system). The present disclosure also contemplates leads being delivered over a stylet which can similarly hold a lead with a preformed shape until the stylet is removed and the lead reverts back to its preformed shape. 
       FIGS.  20 A and  20 B  illustrate implementations  2000  and  2001  of distal portion  1602  of lead  1600 . In some implementations, distal portion  1602  may include distal end  1620  and distal end  1620  may include a flexible portion  2002  so as to allow distal end  1620  to change course when encountering sufficient resistance traveling through the biological tissue of the patient. In some implementations, distal end  1620  may be at least partially paddle shaped, and/or have other shapes. The paddle shape may allow more surface area of distal end  1620  to contact tissue so the tissue is then exerting more force back on distal end  1620 , making distal end  1620  bend and flex via flexible portion  2002 . In some implementations, flexible portion  2002  may comprise a material that flexes more easily relative to a material of another area of distal portion  1602 . For example, flexible portion  2002  may comprise a different polymer relative to other areas of distal portion  1602 , a metal, and/or other materials. 
     In some implementations, flexible portion  2002  may comprise one or more cutouts  2004 . The one or more cutouts  2004  may comprise one or more areas having a reduced cross section compared to other areas of distal portion  1602 . The one or more cutouts  2004  may be formed by tapering portions of distal portion  1602 , removing material from distal portion  1602 , and/or forming cutouts  2004  in other ways. The cutouts may increase the flexibility of distal end  1620 , increase a surface area of distal end  1620  to drive distal end  1620  in a desired direction, and/or have other purposes. Cutouts  2004  may reduce a cross-sectional area of distal end  1620 , making distal end  1620  more flexible, and making distal end  1620  easier to deflect. Without such cutouts, for example, distal end  1620  may be too rigid or strong, and drive lead  1600  in a direction that causes undesirable damage to organs and/or tissues within the anterior mediastinum (e.g., the pericardium or heart). 
     In some implementations, the one or more areas having the reduced cross section (e.g., the cutouts) include a first area (e.g., cutout)  2006  on a first side  2008  of distal end  1620 . The one or more areas having the reduced cross section (e.g., cutouts) may include first area  2006  on first side  2008  of distal end  1620  and a second area  2010  on a second, opposite side  2012  of distal end  1620 . This may appear to form a neck and/or other features in distal portion  1602 , for example. 
     In some implementations, as shown in  FIG.  20 B , the one or more areas having the reduced cross section may include one or more cutouts  2060  that surround distal end  1620 . Referring back to  FIG.  18   , in some implementations, distal portion  1602  may have a surface  1820  that includes one or more electrodes  1604 , and a cut out  1822  in a surface  1824  of distal end  1620  opposite surface  1820  with one or more electrodes  1604 . This positioning of cutout  1822  may promote a bias of distal end  1620  back toward proximal shoulder  1608  ( FIG.  16   ) of lead  1600 . In some implementations, cutout  1822  may create a bias (depending upon the location of cutout  2060 ) acutely in direction  1804  or obtusely in direction  1806 . Similarly, alternative cutouts  2060  may be inserted to bias distal end  1620  in other directions. 
     Returning to  FIGS.  20 A and  20 B , in some implementations, flexible portion  2002  may be configured to cause distal end  1620  to be biased to change course in a particular direction. Distal end  1620  may change course in a particular direction responsive to encountering resistance from biological tissue in a patient, for example. In some implementations, biasing distal end  1620  to change course in a particular direction may comprise biasing distal end  1620  to maintain electrodes  1604  on a side of distal portion  1602  that faces the heart of the patient. For example, distal end  1620  may be configured to flex or bend to push through a resistive portion of biological material without twisting or rotating to change an orientation of electrodes  1604 . 
     In some implementations, distal portion  1602  may include a distal tip  2050  located at a tip of distal end  1620 . Distal tip  2050  may be smaller than distal end  1620 . Distal tip  2050  may be more rigid compared to other portions of distal end  2050 . For example, distal tip  2050  may be formed from metal (e.g., that is harder than other metal/polymers used for other portions of distal end  1620 ), hardened metal, a ceramic, a hard plastic, and/or other materials. In some implementations, distal tip  2050  may be blunt, but configured to push through biological tissue such as the endothoracic fascia, and/or other biological tissue. In some implementations, distal tip  2050  may have a hemispherical shape, and/or other blunt shapes that may still push through biological tissue. 
     In some implementations, distal tip  2050  may be configured to function as an electrode (e.g., as described herein). This may facilitate multiple sense/pace vectors being programmed and used without the need to reposition electrical lead  1600 . For example, once the electrical lead  1600  is positioned, electrical connections can be made to the electrodes  1604  and cardiac pacing and sensing evaluations performed. If unsatisfactory pacing and/or sensing performance is noted, an electrical connection may be switched from one of the electrodes  1604  to the distal electrode  2050 . Cardiac pacing and/or sensing parameter testing may then be retested between one of the electrodes  1604  and the distal electrode  2050 . Any combination of two electrodes can be envisioned for the delivery of electrical therapy and sensing of cardiac activity, including the combination of multiple electrodes to create one virtual electrode, then used in conjunction with a remaining electrode or electrode pairing. Additionally, electrode pairing may be selectively switched for electrical therapy delivery vs. physiological sensing. 
     Returning to  FIG.  16   , in some implementations, at least a portion of distal portion  1602  of lead  1600  may comprise two parallel planar surfaces  1650 . One or more electrodes  1604  may be located on one of the parallel planar surfaces, for example. Parallel planar surfaces  1650  may comprise elongated, substantially flat surfaces, for example. (Only one parallel planar surface  1650  is shown in  FIG.  16   . The other parallel planar surface  1650  may be located on a side of distal portion  1602  opposite electrodes  1604 , for example.) In some implementations, at least a portion  1652  of distal portion  1602  of lead  1600  may comprise a rectangular prism including the two parallel planar surfaces  1650 . 
     Because the proximal end of the distal portion  1602  may be positioned within the intercostal muscle tissue (while the distal end of the distal portion  1602  resides in the mediastinum), the elongated, substantially flat surfaces of proximal end of the distal portion  1602  may reduce and/or prevent rotation of distal portion  1602  within the muscle tissue and within the mediastinum. In contrast, a tubular element may be free to rotate. In some implementations, distal portion  1602  may include one or more elements configured to engage and/or catch tissue to prevent rotation, prevent egress and/or further ingress of distal portion  1602 , and/or prevent other movement. Examples of these elements may include tines, hooks, and/or other elements that are likely to catch and/or hold onto biological tissue. In some implementations, the bending of distal portion  1602  (e.g., as described above related to  FIG.  18   ) may also function to resist rotation and/or other unintended movement of distal portion  1602  in a patient. Distal portion  1602  may also be designed with multiple segments, with small separating gaps between each segment, designed to increase stability within the tissue, increase the force required for lead retraction or to promote tissue ingrowth within the distal portion  1602 . 
     In accordance with certain disclosed embodiments, the present disclosure contemplates systems and methods that include placing a lead having both defibrillation and cardiac pacing electrodes at an extravascular location within a patient. The extravascular location can be in a mediastinum of the patient, and specifically may be in a region of the cardiac notch or on or near the inner surface of a patient&#39;s intercostal muscle. As such, some placement methods can also include inserting the lead through an intercostal space associated with the cardiac notch of the patient. 
       FIG.  21 A  depicts an exemplary junction box  2100  that can facilitate connections between the lead and its control and sensing systems. Such connections can be provided to provide pass through between the various pacing and defibrillation electrodes on the lead and the various input connections on the defibrillation source, one example being to an implantable ICD with a DF-4 connector. In the example implementation shown, the previously described leads can have corresponding junction box connections ( 2132 A,  2134 A,  2136 A,  2138 A,  2142 A,  2144 A,  2146 A,  2148 A) on the lead side of the junction box. The electrodes can be connected via a single lead  2110 A (e.g., a multi-wire cable) at the connector cable side of the junction box. There can also be dedicated connections  2150 A,  2152 A for a pacing anode and cathode. The junction box can also have a lead side connection  2120 A to the coil body itself (e.g., to a housing or grounding mesh) and corresponding SVC connection  2170 A. Cathode connection  2152 A can be connected to a corresponding “tip” connection  2140 A. Anode connection  2150 A can be connected to a corresponding “ring” connection  2160 A. 
     An exemplary method utilizing the leads described above is shown in the flowchart of  FIG.  21 B . In implementations where defibrillation electrodes are disposed on different locations of a lead, as described above, defibrillation pulses will propagate in different directions. In such implementations, the electrodes can also provide sensing information allowing determination of which defibrillation electrodes are directed at the heart in a manner to optimize defibrillation. With such a determination, the defibrillation pulses can be delivered through the optimal electrodes. 
     One exemplary method can include, at  2110 B, receiving sensor data at a sensor (e.g., any disclosed electrode or other separate sensor), where the sensor data can be representative of electrical signals (e.g., from a heartbeat). At  2120 B, an algorithm can determine, based on the sensor data, an initial set of electrodes on a defibrillation lead including more than two defibrillation electrodes, from which to deliver a defibrillation pulse. The initial electrode set can be one estimated to be most directed toward the heart and thereby most appropriate for defibrillation (for example, based on determining relative strengths of the signals detected by different sensing electrodes). At  2130 B, a defibrillation pulse can be delivered with the initial set of electrodes. At  2140 B, post-delivery sensor data can be received, such as by the sensor(s) described above. At  2150 B, a determination can be made, based at least on the post-delivery sensor data whether the defibrillation pulse successfully defibrillated the patient. At  2160 B, if necessary, an updated set of electrodes which to deliver a subsequent defibrillation pulse can be determined, with the process optionally repeating starting at  2130 B with the delivery of the subsequent defibrillation pulse. 
     In step  2150 B, the determination as to whether defibrillation was successful may include receiving signals representative of the current heart rhythm and comparing to an expected or desired heart rhythm that would be reflective of a successful defibrillation. In step  2160 B, determining a new set of electrodes may include, for example, switching to some electrodes on the opposite side of the lead. The determination may also result in using a different set of electrodes on the same side of the lead. In fact, any combination of defibrillation electrodes on the lead, or in combination with electrodes located off of the lead (for example, on the housing of an associated pulse generator) may be utilized, including reversing the electrical polarity of the defibrillation shock. The process of delivering defibrillation energy and selecting different electrode pairings can repeat, cycling through different combinations, until a successful defibrillation is detected. Again referring to step  2150 B, once a defibrillation configuration is determined that successfully defibrillates the heart, the system can retain that configuration so that it can be used for the first defibrillation delivery during a subsequent episode with the patient, thereby increasing the likelihood of successful defibrillation with the first delivered shock for future events. 
       FIG.  22    illustrates an example of an electrode  1604 . In some implementations, an electrode  1604  may be formed from a conductive metal and/or other materials. Electrodes  1604  may be configured to couple with distal portion  1602  of lead  1600 , proximal portion  1606  (e.g., wiring configured to conduct an electrical signal from a controller) of lead  1600 , and/or other portions of lead  1600 . In some implementations, distal portion  1602  may comprise a rigid material, with an area of distal portion  1602  around electrodes  1604  comprising a relatively softer material. One or more electrodes  1604  may protrude from distal portion  1602  of lead  1600  (e.g., as shown in  FIG.  16   ). Electrodes  1604  may be configured to provide electrical stimulation to the patient or to sense electrical or other physiologic activity from the patient (e.g., as described above). In some implementations, one or more electrodes  1604  may include one or both of corners  2200  and edges  2202  configured to enhance a current density in one or more electrodes  1604 . In some implementations, at least one of the electrodes  1604  may comprise one or more channels  2204  on a surface  2206  of the electrode  1604 . In some implementations, at least one of the one or more electrodes  1604  may comprise two intersecting channels  2204  on surface  2206  of the electrode  1604 . In some implementations, the channels  2204  may be configured to increase a surface area of an electrode  1604  that may come into contact with biological tissue of a patient. Other channel designs are contemplated. 
       FIG.  23    illustrates a cross section  2300  of example electrode  1604 . In some implementations, as shown in  FIG.  23   , at least one of the one or more electrodes  1604  may be at least partially hollow  2302 . In such implementations, an electrode  1604  may include a hole  2304  configured to allow the ingress of fluid. In some implementations, an electrode  1604  may include a conductive mesh (not shown in  FIG.  23   ) within hollow area  2302 . The conductive mesh may be formed by conductive wiring, a porous sheet of conductive material, and/or other conductive meshes electrically coupled to electrode  1604 . In some implementations, an electrode  1604  may include electrically coupled scaffolding within hollow area  2302 . The scaffolding may be formed by one or more conductive beams and/or members placed in and/or across hollow area  2302 , and/or other scaffolding. 
     These and/or other features of electrodes  1604  may be configured to increase a surface area and/or current density of an electrode  1604 . For example, channels in electrodes  1604  may expose more surface area of an electrode  1604 , and/or create edges and corners that increase current density, without increasing a size (e.g., the diameter) of an electrode  1604 . The corners, hollow areas, conductive mesh, and/or scaffolding may function in a similar way. 
     In some implementations, an anti-inflammatory agent may be incorporated by coating or other means to electrode  1604 . For example, a steroid material may be included in hollow area  2302  to reduce the patient&#39;s tissue inflammatory response. 
       FIG.  24    illustrates an embodiment of a lead  2400  with parallel planar surfaces that include one or more electrodes. This electrical lead (or simply “lead”) for implantation in a patient is shown as having a distal portion  2402  (e.g., a portion deployed in a patient) and a proximal portion  2404 . The distal portion can include one or more electrodes that are configured to generate therapeutic energy for biological tissue of a patient. The proximal portion can be coupled to the distal portion and configured to engage a controller that can be configured to cause the one or more electrodes to generate therapeutic energy. 
     At least a portion of the lead (e.g., the distal portion) may include two parallel planar surfaces that can form a rectangular prism. Various embodiments of the leads described herein can thus provide a distal portion configured for extravascular implantation. For example, these planar surfaces are well-suited for implantation near and/or along a patient&#39;s sternum. As used herein, the term “rectangular prism” refers to a lead having rectangular sides and/or cross section. Some sides/cross-sections may be square, as such is a type of rectangle. Also, a “rectangular prism” allows for small deviations from being perfectly rectangular. For example, edges may be rounded to prevent damage to patient tissues and some rectangular faces may have a slight degree of curvature (e.g., less than 30°). 
     The distal portion of the lead may include defibrillation electrodes or cardiac pacing electrodes. In some embodiments, the electrodes on the lead may include both defibrillation electrodes and cardiac pacing electrodes. One embodiment, depicted in  FIG.  24   , shows a lead body  2420  with a top side  2430 , which may include electrodes  2432 ,  2434 ,  2436 ,  2438 . Also shown as an inset is part of the bottom side  2440  of the lead (which would normally be obscured by the perspective view). The bottom side can have a similar, or identical, set of electrodes ( 2442 ,  2444 ,  2446 ,  2448 ). In the embodiments described herein, particularly those referencing  FIGS.  24 - 27   , electrodes are may described with reference to a particular “side” of a lead. However, it is contemplated that electrodes can be configured to provide directional stimulation from any side of the lead body. For example, rather than having electrodes present on the top side and the bottom side of a directional lead, there may be electrodes present on a top side and a left side of the directional lead. Accordingly, no particular combination, disposition, or shape of the disclosed electrodes should be considered essential to the present disclosure, other embodiments not specifically described are contemplated. 
     As shown in  FIG.  24   , the electrodes can be thin metallic plates (e.g., stainless steel, copper, other conductive materials, etc.) of a generally planar shape. The thin metallic plates can be rectangular (as shown in  FIG.  24   ) but may also be elliptical (as shown in  FIG.  25 A ). The panel electrodes may have rounded corners or edges to avoid damaging patient tissue. Certain embodiments of the thin metallic plates can be on one or both of the two parallel planar surfaces. 
     The embodiment of  FIG.  24    depicts defibrillation panel electrodes along with a pacing anode  2450  and pacing cathode  2452 . Although the embodiments depicted in the figures include pacing electrodes only on the bottom of the lead, it is contemplated that the lead may alternatively include pacing electrodes on either or both sides of the lead. In addition, the location of the anode and cathode may be reversed or moved to different locations on the lead. Additionally, multiple pacing anodes  2450  or pacing cathodes  2452  may be included on the same side of the lead. 
     While the embodiment of  FIG.  24    depicts four top defibrillation electrodes and four bottom defibrillation electrodes, it is contemplated that various other arrangements and placements may be utilized, for example, two defibrillation electrodes on top and two defibrillation electrodes on bottom, etc. Also, it is contemplated that any of the corresponding top and bottom defibrillation electrodes may be connected, thereby delivering directional electrical energy simultaneously away from the top side and the bottom side of the lead body (e.g., electrodes  2432  and  2442  may be connected or formed as a single conductive element that extends through the lead body). 
       FIG.  24    also depicts leads wires ( 2432   a ,  2434   a ,  2436   a ,  2438   a ,  2442   a ,  2444   a ,  2446   a ,  2448   a ,  2450   a ,  2452   a ) that extend through or along the lead body and connect to their respective electrodes. The expanded top view illustrates the lead wires ( 2432   a ,  2434   a ,  2436   a ,  2438   a ) for the electrodes ( 2432 ,  2434 ,  2436 ,  2438 ) on the top of the lead. The lead wires can conduct defibrillation and pacing pulses and/or sensing signals to and/or from a connected pulse generator or computer that controls or processes signals. Similar to other embodiments described herein, the illustrated defibrillation electrodes can be energized in any combination to provide specific defibrillation vectors for delivering defibrillation pulses. Such energization can include varying the current through the defibrillation electrodes and thereby varying the defibrillation energy delivered to the heart. Furthermore, multiple or all electrodes may be electrically tied together within the lead body such that only one lead wire emerges at the distal portion  2404 . In some embodiments, the pacing cathode and anode are independently routed to the distal portion of the lead along with one defibrillation lead wire that is connected to all of the defibrillation electrodes. Alternatively, the pacing cathode may be independent; however, the pacing anode and defibrillation electrodes are electrically tied together within the lead body. In some instances, the defibrillation electrodes can act as the pacing anode for cardiac sensing and pacing therapies, while also serving as the defibrillation electrodes during defibrillation energy delivery. Additionally, redundant wires may be placed to ensure electrical connection with the various electrodes in the even that one wire is compromised. 
     While the depicted components (e.g., directional lead, lead body, electrodes, anode, cathode, etc.) can be designed to various dimensions, in an exemplary implementation, the lead body may have a width of approximately 5 mm and a thickness of approximately 2 mm, with panel electrodes being approximately 20 mm in length by 5 mm in width. Also, the pacing anodes and/or cathodes can have an approximately a 2-5 mm diameter. As used herein, the term “approximately,” when describing dimensions, means that small deviations are permitted such as typical manufacturing tolerances but may also include variations such as within 30% of stated dimensions. 
     The embodiments described herein are not intended to be limited to two opposite sides of a planar lead body. The teachings can apply similarly to a lead body that is round, with electrodes located at different angles around the circumference of the lead body. 
       FIG.  25 A  illustrates an embodiment of a lead  2500  with elliptical electrodes  2502 . Such elliptical electrodes can be similar in many respects to the rectangular thin metallic plate electrodes described above but can have the benefit of providing a different current distribution to the patient than rectangular electrodes. 
       FIG.  25 B  illustrates an embodiment similar to the embodiment described with reference to  FIG.  25 A  but instead of the electrodes being planar (e.g., a continuous sheet or plate) the defibrillation electrodes may be constructed as elliptical spiral coils  2520 . Such spiral electrodes can have electrical current passed along the conductor in a spiral pattern. The conductors forming the spiral may have cross-sections that are round (e.g., wire), rectangular (e.g., flat), etc. The dimensions of the overall spiral can be similar to those described above with regard to the planar electrodes of  FIG.  24   . The configuration of the spiral can be such that there is a sufficient spacing (e.g., approximately 0.05 mm) to allow for flexibility which eases the delivery of the lead as compared to rigid panels. It is contemplated that the spiral can be constructed such that most of the area of the electrode is occupied by conductor, though in some implementations, the central portion may not be fully covered or may be covered in a looser spiral to manufacturing constraints. In some embodiments, the surface area of the spiral coil can be greater than 50%, 60 to 70%, 80 to 90%, or greater than 95% of the surface area enclosed by the largest perimeter of the spiral. 
     As shown in the magnified inset, spiral electrodes may have an inner termination  2522  and an outer termination  2524 . The inner and outer terminations can be connected to corresponding connecting lead wires  2530  and such lead wires may extend through the lead body similarly to the configuration described with respect to  FIG.  24   . Pairs of leads (i.e., a lead for the inner termination and a lead for the outer termination) may be braided to reduce electrical interference. However, in some implementations, there may be a single lead connected to either the inner termination or the outer termination of the spiral. In such implementations, only the patient tissue acts as a return for the delivered current. 
       FIG.  26    illustrates an embodiment of a lead  2600  that has embedded electrodes  2610 . Such embedded electrodes  2610  can be similar to previous embodiments in that they provide directional stimulation. To provide this directional stimulation, electrical energy from the embedded electrodes may be partially blocked by the insulating lead body. As shown in the depicted embodiment, embedded electrodes can be partially embedded in the portion of the distal portion of the lead having the two planar parallel surfaces. In this way, the partially embedded electrodes can have an embedded portion and an exposed portion. 
     In the embodiment of  FIG.  26   , the embedded electrodes are shown as helical coils that are oriented in the longitudinal direction (i.e., along the lengthwise direction of the lead body). The inset of  FIG.  26    shows a simplified end view of the lead body with a portion of the embedded electrode being outside the lead body and the remainder of the embedded electrode being inside the lead body (as indicated by the dashed lines). As can be seen, the portion of the embedded electrode outside the lead body can thus have a similar surface area to the previously described planar electrodes. However, due to the helical shape of the embedded electrode, the portion that is extending from the lead body can have a greater vertical extent (i.e., can bulge outward) as compared to a thin metallic plate electrode and thus increase the available surface area. 
     The electrodes depicted in  FIG.  26    are configured such that the exposed portion is on only one of the two planar parallel surfaces. However, it is contemplated that in other embodiments the electrodes may have portions that extend from more than one face. For example, were the electrode larger in diameter and/or shifted downward in the inset, there could be portions extending from both of the two planar parallel surfaces. In this way, the embedded electrode can provide directional stimulation, but in multiple directions, similar to embodiments where there may be top and bottom electrodes (e.g., in  FIG.  24   ). In some embodiments, the degree of embeddedness can vary. For example, the exposed portion can include at least 25%, 50%, 75%, etc. of the partially embedded electrode. 
     As shown, the embedded electrode can be a circular helical coil (i.e., as if wrapped around a cylindrical object), however, other embodiments can have the embedded electrode be an elliptical helical coil (i.e., as if the object around which the wire was wrapped had an elliptical rather than circular cross-section). Yet other embodiments can have the embedded electrode be a solid electrode having a circular, elliptical, or rectangular cross-section. Some elliptical or rectangular embodiments can beneficially provide greater surface area while keeping the thickness of the coil (e.g., in the semimajor direction or in a thinner direction) at a minimum to reduce the overall thickness of the directional lead. 
     Some embodiments of partially embedded electrodes can include additional structural feature(s) to increase surface area beyond that provided by their cross-section. Examples of additional structural features can include conductive mesh. The conductive mesh may be formed by conductive wiring, a porous sheet of conductive material, and/or other conductive meshes electrically coupled to partially embedded electrode. These and/or other features of partially embedded electrodes may be configured to increase a surface area and/or current density of an electrode. For example, channels in partially embedded electrodes may expose more surface area, and/or create ridges, edges, and corners that increase current density, without increasing a size (e.g., the diameter) of an electrode. Implementations having such corners, hollow areas, conductive mesh, and/or scaffolding may function in a similar way. 
     Other embodiments of the partially embedded electrode can include an additional structural feature to increase current density beyond that provided by its cross-section and may also include a feature to increase current density at particular location(s). For example, as described above, ridges, edges, and corners may also have the effect of increasing current density due to charge accumulation. Other embodiments that may have increased surface area and/or current density can include electrodes with surfaces that have been treated by a sputtering process to create conductive microstructures or coatings that impart a texture to the electrode surface. 
       FIG.  27    illustrates an embodiment of a lead  2700  including coil electrodes  2720  that are wrapped around the lead. As shown, the electrodes can be coils wrapped around a portion of the distal portion of a lead that has two parallel planar surfaces. As used herein, the term “wrapped” means that the conductor (e.g., wire) is wound in a somewhat helical manner around the lead. The wrapping may have deviations from being a perfect helix in that the wrapping may be looser in some places and tighter others, for example, to facilitate flexible portions of the lead or to avoid obstruction or contact of other elements such as other electrodes. It is contemplated that while most implementations involve winding a conductor around the lead, it is also possible that equivalent structures can be used such as hollow bands, connected plates, etc. that can provide substantially the same circumferential coverage. 
     To provide directional stimulation capability consistent with the present disclosure, as shown in  FIG.  27   , there may be an insulating mask  2710  over a portion of the coils(s) on one of the parallel planar surfaces. Such a mask can be, for example, an electrically insulating or absorbing material (e.g., rubber, plastic, etc.) to prevent or reduce the transmittal of electrical energy. Such masking can be continuous as shown or can be segmented to only cover one or more individual electrodes. The masks need not be on the same side of the directional lead. For example, some electrodes may be masked on the top side, and other electrodes may be masked on the bottom side, thereby providing options for directional stimulation. Similarly, some implementations can have masking on multiple sides. For example, masking could be applied to three of the four sides of the depicted directional lead thus exposing the portion of the electrode on only one side. 
       FIG.  28    illustrates an embodiment of a lead  2800  that has embedded electrodes  2610  and pacing electrode  2810  at a distal end of lead  2800 .  FIG.  28    is an embodiment similar to that of  FIG.  26    but having pacing electrode  2810  at the distal end. Such an embodiment can provide an increased distance between pacing electrodes. 
       FIG.  29    illustrates an embodiment of a lead  2900  including coil electrodes  2720  that are wrapped around the lead and pacing electrode  2910  at a distal end of lead  2800 .  FIG.  29    is an embodiment similar to that of  FIG.  27    but having pacing electrode  2910  at the distal end. Such an embodiment can provide an increased distance between pacing electrodes. 
     While the embodiments of  FIGS.  24 - 29    depict specific numbers and disposition of electrodes, it is contemplated that various other arrangements and dispositions may be utilized, for example, 1, 2, 3, 5, etc. electrodes arranged with varying spaces, etc. 
     In addition to the lead designs previously presented, the present disclosure also contemplates splitting leads whereby a delivery tool can facilitate different portions of the splitting lead spreading out in a particular manner during delivery (e.g., separating sub-portions similar to those described above). 
     In another lead embodiment, depicted in  FIGS.  30 A and  30 B , an electrical lead  3010  may be configured to have its distal portion split apart into two or more significant portions and travel in different directions during implantation in a patient (e.g., as a result of engaging with ramps, as described further below). Such designs are referred to herein as “splitting leads.”  FIGS.  30 A and  30 B  depicts one exemplary embodiment of a splitting lead. 
     Similar to other leads of the present disclosure, the splitting lead can have a distal portion  3020  having electrode(s) that are configured to generate therapeutic energy for biological tissue of the patient. The electrodes can include any combination of defibrillation electrodes and/or cardiac pacing electrodes. Also, as partially shown in  FIG.  30 B , the lead can have a proximal portion  3030  coupled to the distal portion and configured to engage a controller. The controller can be configured to cause the electrode(s) to generate the therapeutic energy, e.g., via transmitting current through wires to the various electrodes similar to other disclosed embodiments such as that of  FIG.  24   . 
     In the depicted embodiment, the distal portion is configured to split apart into sub-portions  3040  that travel in multiple directions during implantation into the patient. In this example, a delivery system  3000  is inserted into a patient (e.g., through an intercostal space in the region of the cardiac notch) and, after insertion, lead  3010  is advanced and sub-portions  3040  of the lead split off in different directions. While the example of  FIGS.  30 A and  30 B  depicts the lead splitting off in two different directions, the present disclosure contemplates designs following the teachings herein that split off in more directions (e.g., three directions, four directions, etc.). 
     The splitting lead designs disclosed herein may be particularly useful for ICD/defibrillation applications as they can provide for additional lead length and thus additional area for electrode surface. However, the present disclosure contemplates the use of splitting lead designs in pacing applications as well. In some applications, the splitting lead designs disclosed herein can include both pacing and defibrillation electrodes, as taught throughout this disclosure. 
       FIG.  31 A  depicts an exemplary placement for a splitting lead  3010  in which a lead delivery system (or merely “delivery system”) can be inserted into the patient, for example, through an intercostal space associated with or in the region of the cardiac notch of the patient. Exemplary methods of placing the splitting lead can include operating the delivery system to place the distal portion of the lead in an extravascular location of the patient. For example, the extravascular location can be in a mediastinum of the patient, in the region of the cardiac notch, and/or on or near the inner surface of an intercostal muscle. The lead&#39;s wires  3120  can extend to a controller  3130 , which may be implanted in the patient. 
     After insertion, the delivery system  3000  can be operated such that lead  3010  can be advanced so that the distal portion of lead  3010  splits apart into two portions that travel in multiple directions within the patient. As shown in  FIG.  31 A , the distal portion of lead  3010  can split so that sub-portions  3040  travel in opposite directions parallel to a sternum of the patient. 
       FIG.  31 B  depicts another exemplary placement for a splitting lead  3110  where the distal portion of the lead splits apart into two sub-portions  3140  that travel in directions approximately 100° apart and under the sternum of the patient. Additional extravascular placements are contemplated and can include the distal portion of the lead splitting into more sub-portions (e.g., the distal portion of the lead may split into three portions that travel in directions approximately 90° apart and parallel or perpendicular to the sternum of the patient. 
       FIG.  32    illustrates another view of an exemplary splitting lead, exiting an exemplary delivery system  3000 . Such splitting leads can allow for increased total length and electrode surface area while facilitating implantation. 
     In one embodiment, the distal portion of the lead can be configured to split apart into two sub-portions having a combined length of approximately 6 cm (e.g., ±up to 1 cm). Numerous other lengths are contemplated, for example, approximately 4, 5, 7, 10, etc., centimeters. The two sub-portions can be of equal length or may have different lengths. For example, the distal portion can be configured to split apart into two sub-portions comprising 60% and 40% respectively of their total combined length. Other implementations can include those with approximately 55%/45%, 65%/35%, 70%/30%, etc., ratios of lengths and the ratios can be determined in order to provide optimal anatomical coverage given the implantation location. 
     For example, the distal portion can be configured to split apart into two sub-portions having different lengths. In some embodiments, the splitting lead can include a cathode located on a shorter sub-portion of the two different length sub-portions and an anode located on a longer sub-portion, an anode located on a shorter sub-portion of the two different length sub-portions and a cathode located on a longer sub-portion, etc. 
     Similar to the embodiments described with reference to  FIG.  24   , the sub-portions can include parallel planar surfaces. Similar to other embodiments, these sub-portions can then form rectangular prisms including the two parallel planar surfaces. As shown in  FIG.  32   , the distal portion can be wider (W) than it is thick (T). 
     During deployment, the lead is advanced through the tip of the delivery system (described further below). After placement of the lead in the patient, the delivery system can then be withdrawn (e.g., as indicated by the direction of the arrow in  FIG.  32   ). To facilitate withdrawal of the delivery system after the lead has been implanted, the proximal portion of the lead can be configured to be thinner than the distal portion of the lead (see, e.g., location  3200  in  FIG.  32   , identifying the location where the proximal portion of the lead thins compared to the distal portion of the lead). In this manner, the lead can proceed directly through the tip of the delivery system  3000 . 
     It is contemplated that each of the split distal portions of the splitting lead designs disclosed herein may incorporate features described above in conjunction with non-splitting lead designs. 
     For example, the sub-portions can include distal ends  3050  having flexible portions so as to allow the distal ends to change course when encountering sufficient resistance traveling through the biological tissue of the patient. For example, if the distal ends encounter bone, muscle, etc., the flexible portions can allow the distal ends to still deploy within the patient without necessarily affecting or damaging the resisting biological tissue. Such flexible portions can include a material that flexes more easily relative to material of other areas of the sub-portions. The material can be rubber, soft plastic, etc., which may be more flexible than the materials used for the rest of the sub-portions (e.g., metal, hard plastic, etc.). The flexible portions can include one or more cutouts  3060 , which can be one or more areas having a reduced cross section compared to other areas of the sub-portions. In other embodiments, the flexible portions can be configured to cause the distal ends to be biased to change course in a particular direction. For example, such biasing can include using flexible materials having different flexibility in different portions, reinforcements such as rods that prevent flexing in certain directions, etc. 
     The particular shape of the distal ends can vary but, as shown in  FIG.  32   , the distal ends can be at least partially paddle shaped. In other embodiments, they may be more pointed to have a triangular or wedge shape or may be more rectangular to form a rectangular prism similar to the majority of the distal portion as shown. 
     Some embodiments of splitting leads can implement the use of shape memory material to enable deployment in a particular manner or in particular directions. For example, the sub-portions can include a shape memory material configured to bend in a predetermined direction when the sub-portions exit the delivery system. In this way, the delivery system can contain the sub-portions until they clear the internal structure of the delivery system and they will then deploy in their respective predetermined directions. Examples of such predetermined directions can result in creating an acute angle shape between the sub-portions and the proximal portion. In some embodiments, the sub-portions can be further configured to move in a direction opposite the predetermined direction responsive to the shape memory material being heated to body temperature. For example, some implementations can benefit from having the lead held at a lower temperature for ease of loading into the delivery system and/or deployment. Once introduced into the body, after an appropriate length of time, the sub-portions would then heat to body temperature and as such would become deployed in a direction opposite the predetermined directions (e.g., toward the heart). In some implementations, movement in the direction opposite the predetermined direction can create a ninety degree shape, or an obtuse angle shape between the sub-portions and the proximal portion. 
     In some embodiments, for example, to assist in deployment through tissue that may provide resistance, the sub-portions of a splitting lead can include distal ends with distal tips  3070  that can be smaller than the distal ends (e.g., can be pointed or wedged-shaped, or have a ball shape, etc.). Some such implementations can also benefit by having distal tips configured to be more rigid compared to other portions of the distal end. 
       FIG.  33    illustrates an embodiment of a splitting lead that includes electrodes wrapped around the distal portion of the lead. A splitting lead  3010  may, for example, have electrodes  3330  wrapped around the sub-portions  3040  of the lead that travel in multiple directions during implantation (e.g., as a result of engaging with ramps, as described further below). In an embodiment where the sub-portions are rectangular prisms, the one or more electrodes wrapped around the sub-portions may be elliptical in shape. When an electrode is wrapped in such a way, the present disclosure refers to its shape as elliptical, even though the wrapped electrode may not be purely oval in shape—since such electrodes are still somewhat oval and are longer in one dimension (e.g., width dimension of the sub-portion) than in another dimension (e.g., thickness dimension of the sub-portion). See  FIG.  32    for examples of the width W and thickness T of a sub-portion. 
     In addition to electrodes being wrapped around the sub-portions  3040 , electrode(s) may also be wrapped around a proximal part  3320  of the distal portion of the lead, specifically, the part of the distal portion that does not travel in different directions during implantation. Such wrapped electrodes  3340  can provide additional electrode surface area and may also be separately energized to deliver therapeutic energy along additional vectors. The present disclosure contemplates that such wrapped electrodes may be utilized for defibrillation and/or pacing. 
     The exemplary embodiment of  FIG.  33    also depicts optional pacing electrodes  3350  located near the distal ends of sub-portions. In other implementations, the pacing electrodes  3350  may not be as close to the distal ends as they are in  FIG.  33    (i.e., they may not be on the “flexible” portions previously-described but instead just proximal to those flexible portions). In still other implementations, the pacing electrodes may be located on only one of the sub-portions, for example, if that particular sub-portion will be located within the patient at a better location with respect to the heart for pacing. In some implementations, defibrillation electrodes can be placed proximal to the pacing electrodes. 
       FIG.  34    illustrates an embodiment of a splitting lead further including an electrode extension. The exemplary lead can include a distal portion configured to split apart into sub-portions  3040  that travel in multiple directions during implantation into the patient. The lead can also include an electrode extension  3420  that increases a distance between an electrode  3450  and one or more other electrodes on the distal portion of the lead and/or facilitates contact of the electrode  3450  with patient tissue. This embodiment is similar to other splitting leads described herein and may also contain any of the features of such (e.g., wrapped electrodes, pacing electrodes on sub-portions, etc.). Electrode extension  3420  can be delivered via the delivery system  3000  as part of delivery of the splitting lead (which may include indentations in its sub-portions  3040  so that electrode extension  3420  better fits between the sub-portions  3040  when they fold together inside the delivery system). Electrode extension  3420  can extend and move along the main axis of the delivery system (e.g., straight down into the patient), and may be independently deployable and retractable/adjustable so the depth of the electrode tip can be independently set at the time of deployment. Consistent with discussions throughout the present disclosure, electrode extension  3420  may be used in conjunction with other electrodes and can provide additional vectors for the delivery of therapeutic energy. Electrode  3450  can be of any type, for example, a pacing electrode which may act as a cathode or an anode, in conjunction with another electrode elsewhere on the lead. In some embodiments, such an electrode  3450  and electrode extension  3420  form what is referred to herein as a central pacing electrode. 
       FIG.  35    illustrates an exemplary embodiment of a splitting lead that includes a protective collar for an electrode on an electrode extension (e.g., a pacing, sensing or defibrillation electrode). The embodiment also combines features of the splitting lead of  FIG.  33    (having wrapped electrodes around the splitting lead&#39;s sub-portions  3040 ), the leads of  FIGS.  34  and  54    (having a central electrode), and the splitting lead of  FIG.  40 B  (having concavities  4031  and  4033  to allow the splitting lead to fully close and maintain a compact size). In this embodiment, the splitting lead can also include protective collar  3522  that can surround electrode extension  3520 . Such a protective collar can be configured to prevent the electrode from advancing too far into a patient or from perforating patient tissues due to the relatively sharp nature of the electrode by itself. The protective collar can also facilitate the application of contact pressure against patient tissues and can be made of an electrical insulator that can insulate patient tissues from the electrode. While one exemplary splitting lead/electrode configuration is shown in the embodiment of  FIG.  35   , the protective collar and its related features may be utilized with any other embodiments disclosed herein that incorporate an electrode on an electrode extension. 
     With reference to the embodiment depicted in  FIG.  35   , the protective collar  3522  can include a protective collar stopping foot  3524  having a laterally extending portion  3526  that can abut patient tissues at a desired location to prevent further inward deployment of the central pacing electrode. The distance between the distal face  3528  of the protective collar stopping foot and the tip of electrode  3450  can be configured to minimize the likelihood of tissue perforation and also to provide the desired contact pressure against patient tissues. The distance can be, for example, 1 mm, 2 mm, 3 mm, etc. Similar to the embodiment of  FIG.  40 B , the splitting lead embodiment in  FIG.  35    can include various concavities  3529  in the lead body and/or sub-portions that are shaped to receive the protective collar, protective collar stopping foot, and/or the central pacing electrode/electrode extension such that the splitting lead can be fully closed. Furthermore, the protective collar  3522  may include materials impregnated with anti-inflammatory substances, such as steroids, that can prevent the inflammation of tissue. Such substances can be released into the tissue on a time-delayed basis to prevent a tissue inflammation response in an acute and/or chronic manner. 
       FIGS.  36  and  37    illustrate embodiments of splitting leads that have embedded electrodes (see  3630  and  3730  respectively). Such splitting-lead embedded electrodes may include the features of any of the embedded electrodes previously described with regard to  FIG.  26   . 
     The  FIGS.  36  and  37    embodiments depict helical coils that are oriented in the longitudinal direction (i.e., along the lengthwise direction of the sub-portion).  FIG.  36    depicts an embedded electrode  3630  with a circular shaped helical coil (i.e., as if wrapped around a cylindrical object) while  FIG.  37    depicts an embedded electrode  3730  with an elliptical shaped helical coil (i.e., as if wrapped around an object with an elliptical cross-section). Other embodiments could have the embedded electrode be a solid electrode having a circular, elliptical (e.g., oval), or rectangular cross-section. Some elliptical or rectangular embodiments can beneficially provide greater surface area while keeping the thickness of the coil (e.g., in the semimajor direction or in a thinner direction) at a minimum to reduce the overall thickness of the directional lead. 
     As shown in the embodiments of  FIGS.  36  and  37   , the electrodes can be partially embedded in the sub-portions  3040  that travel in multiple directions during implantation. Similar to earlier embodiments, these partially embedded electrodes have an embedded portion  3634 / 3734  and an exposed portion  3632 / 3732 . In the specific examples of  FIGS.  36  and  37   , the splitting leads have sub-portions that each comprise two parallel planar surfaces and the exposed portions of the embedded electrodes are on both of the planar parallel surfaces. 
     Simplified end views of the splitting lead sub-portions are shown in the insets of  FIGS.  36  and  37   , detailing parts of the embedded electrodes that are exposed, and parts that are embedded. As can be seen, the portion of the embedded electrodes that is exposed can have a similar surface area to the previously described electrodes. For example, the exposed portions can include at least 25%, 50%, 75%, etc., of the partially embedded electrode. 
     These embedded electrodes (also referred to herein equivalently as “partially embedded electrodes”) can include additional structural features for increasing surface area and/or current density as described above with reference to  FIG.  26   . Also, when referring herein to “embedded” electrodes, it is contemplated that some implementations may have a small amount of material between the conductive electrode and the patient that does not significantly reduce therapeutic energy and thus the “exposed” portion is still considered exposed. For example, there may be a thin layer of protective coating or the like between the electrode and the patient&#39;s tissue but this thin layer may cause no significant interference with the therapeutic energy provided via the embedded electrode. 
       FIGS.  38  and  39    illustrate embodiments of embedded electrodes that are exposed only on only one side of the sub-portions. Such embedded electrodes will provide more directional stimulation, as discussed above. In the particular cross-sections of the depicted embodiments, the electrodes are helical coils and have an exposed portion on only one of two planar parallel surfaces. 
       FIG.  38    also illustrates that there may be multiple embedded electrodes  3830  on a single sub-portion  3040 .  FIG.  38    is similar to  FIG.  36    but instead of one long embedded electrode, there are two shorter embedded electrodes that may be generally inline with each other (though some offset could be present in certain implementations). The embodiment of  FIG.  39    provides an alternative design where two embedded electrodes  3930  are positioned side-by-side (e.g., parallel) on the same sub-portion  3040 . Such designs can be beneficial in that the splitting of embedded electrodes into sections can provide for a greater number of vectors or can provide for alternative electrode surface areas and current densities. In other embodiments, there may be any number of electrodes besides two (e.g., three, four, five, etc.). 
     The particular embodiment depicted in  FIG.  38    may employ electrodes  3830  for defibrillation and electrodes  3850  for pacing, although it is contemplated that each of the electrodes could be configured to be used for pacing and/or defibrillation. While not shown due to the perspective view, similar electrodes configurations can be utilized on both sub-portions. Moreover, other combinations of defibrillation and pacing electrodes, as discussed throughout this disclosure, may be chosen for the splitting leads. 
       FIG.  40 A  illustrates an embodiment of a lead having offset electrodes  4030  and  4032 . This embodiment is similar to that shown in  FIG.  39    but rather than having two embedded electrodes on each sub-portion  3040  there is one embedded electrode on each sub-portion and the exposed portions of the partially embedded electrodes are offset in order to avoid interference (e.g., contact) when the distal portion of the electrical lead is folded (i.e., before it splits apart into sub-portions that travel in multiple directions during implantation). A simplified view of a folded lead  4010  is depicted by the inset illustrating how such a lead has a smaller form factor than would be possible without such an offset. Additionally, as shown in  FIG.  40 B , sub-portions  3040  may include concavities  4031  and  4033  equally opposing the shapes of exposed electrodes  4030  and  4032 . As shown by the inset section view, when the distal portion of the lead is folded, the exposed portions of the electrodes fit within the concavities of the opposing sub-portion, thereby creating an even smaller form factor when folded. As with other embodiments, the partially embedded electrodes can include pacing electrodes and/or defibrillation electrodes, as well as optionally having a pacing electrode extend between the sub-portions that travel in multiple directions during implantation. 
       FIGS.  41 A,  41 B, and  41 C  illustrate portions of a delivery system deploying a component. The delivery system (for example, the delivery system  200  in  FIGS.  9 A-D  or delivery system  3000  in  FIG.  30 A ) can include a component advancer configured to advance the component into the patient. The delivery system can also include a handle configured to be actuated by an operator. The component advancer can be coupled to the handle and thereby configured to advance the component into the patient by applying a force to a portion of the component in response to actuation of the handle by the operator. Also, the component advancer can be configured to removably engage a portion of the component to deliver the component into the patient. 
     As depicted in the delivery system of  FIG.  30 A , the component can be a splitting lead  3010  having a proximal portion  3030  configured to engage a controller and a distal portion  3020  configured to split apart into sub-portions  3040  that travel in multiple directions during implantation into a patient. To facilitate the deployment of such a splitting lead, the delivery system can include, as shown in  FIG.  41 A , an insertion tip  4110  having a first ramp  4120  configured to facilitate advancement of a first sub-portion into the patient in a first direction. There can be a similar second ramp  4130  (shown in the cross-section view of the tip at the top of  FIG.  41 A ) configured to facilitate advancement of a second sub-portion into the patient in a second direction. 
     As depicted in  FIG.  41 A , the first direction (i.e., the direction in which the first ramp advances the first sub-portion of the lead) can be opposite the second direction (i.e., the direction in which the second ramp advances the second sub-portion of the lead). In other words, the first direction can be 180° from the second direction. This directional split is also depicted in  FIG.  31 A . 
     In other embodiments, the angle between the first direction and second direction can be approximately 100°, allowing for placement of the sub-portions at least partially under the sternum. This directional split is also depicted in  FIG.  31 B . Other angles between the first direction and second direction (and their associated ramp configurations) are contemplated, for example, 90°, 110°, 120°, etc. 
     In some implementations, the delivery system can include a third ramp (e.g., in addition to the first and second ramps) configured to facilitate advancement of a third sub-portion into the patient in a third direction (e.g., 90° from the first and second directions). This can permit deployment of sub-portions approximately 90° apart and either parallel or perpendicular to the sternum of the patient. 
     In other implementations, at least the first ramp, and optionally the second ramp, may include a gap  4140  configured to facilitate removal of the delivery system after implantation of the splitting lead. An example of how gap  4140  can facilitate removal of the delivery system is depicted in the deployment sequence of  FIGS.  41 A,  41 B, and  41 C . The component (here a splitting lead) is shown in  FIG.  41 A  having the sub-portions of the splitting lead engaging the first ramp and the second ramp to split apart in multiple directions.  FIG.  41 B  then depicts a later stage in delivery showing the gap being wide enough to pass the proximal portion  3030  of the splitting lead, but still thinner than the width of the sub-portions of the splitting lead, which must engage the ramps in order to split off in different directions. Once the sub-portions have split apart such that they no longer engage the ramps, the delivery system can begin to withdraw over the proximal portion of the lead.  FIG.  41 C  depicts the delivery system further withdrawn and the proximal portion  3030  of the lead being further exposed. 
     In another implementation, instead of the first and second ramps being at the same lengthwise position in the insertion tip (i.e., back, to back) the second ramp may be located at a more distal location than the first ramp so that advancement of the second sub-portion will be at a location deeper into the patient. 
     In some embodiments, the ramps may additionally include a taper at their proximal ends to widen the gap in that location. This widening can facilitate advancement of the component through the insertion tip by reducing the likelihood of the component getting stuck inside the gap. 
     To facilitate insertion of the delivery tool into patient tissue, the insertion tip may include a tissue-separating component  4150 . As shown in  FIGS.  41 A,  41 B, and  41 C , the tissue-separating component can be wedge-shaped to separate and/or cut through tissue as needed for insertion. The tissue-separating component may also have a blunted distal end to reduce or avoid damage to tissue, blood vessels, etc. In the same manner as discussed above with regard to the ramps, the tissue-spreading component can include a gap configured to facilitate removal of the delivery system after implantation of the splitting lead. 
     Some embodiments of the insertion tip can include a movable cover configured to cover the gap during implantation. The movable cover can be configured to prevent tissue from accumulating in the gap when the insertion tip is pushed through patient tissue. Such movable covers can include, for example, a cover that can be pulled off when proper insertion depth is reached. In other examples, the cover can include a pivot, hinge, or flap to allow the movable cover to swivel out of the way of the component. 
     As depicted in  FIG.  41 D , other embodiments may incorporate a gap-filling component  4040  on the distal end of the splitting lead to fill the gap between the tissue-separating components. Gap-filling components  4040  may be incorporated on the distal ends of sub-portions  3040  such that, when the splitting lead is folded and loaded into the delivery system, the gap-filling components fit within and fill the gap of the tissue-separating component. Once inserted within the patient tissue, the gap-filling components are deployed with sub-sections  3040 , as described previously with regard to  FIG.  41 A , thereby clearing the gap and allowing for proximal portion  3030  to travel through the gap, as shown in  FIGS.  41 B and  41 C . 
     As described above, in some implementations, system  200  ( FIG.  3   ) includes the electrical lead  1600  ( FIG.  16   ), handle  300  ( FIG.  3   ), component advancer  302  ( FIG.  3   ), first and second insertion tips  304 ,  306  ( FIG.  3   ), and/or other components. First insertion tip  304  and second insertion tip  306  may be configured to close around a distal tip of the electrical lead when the electrical lead is placed within component advancer  302 . First insertion tip  304  and second insertion tip  306  may be configured to push through biological tissue when in a closed position and to open to enable the electrical lead to exit from component advancer  302  into the patient. Component advancer  302 , first insertion tip  304 , and second insertion tip  306  may be configured to maintain the electrical lead in a particular orientation during the exit of the component from component advancer  302  into the patient. Also as described above, first insertion tip  304  may include a ramped portion configured to facilitate advancement of the component into the patient in a particular direction, and/or the electrical lead may be configured to bend in a predetermined direction after the exit of the component from the component advancer (e.g., because of its shape memory properties, etc.). 
       FIG.  42    illustrates components of delivery system  200  configured to load (or reload) a component (e.g., an electrical lead  1600  shown in  FIG.  16   ) into delivery system  200 . In some implementations, to facilitate reloading delivery system  200 , an operator may thread proximal portion  1606  ( FIG.  16   ) of lead  1600  backwards through insertion tips  304 ,  306  ( FIG.  3   ), through pusher tube  1300  (in an implementation shown in  FIG.  13   ) and out through an opening  4230  in handle  300 . In some implementations, component advancer  302  may be configured to reload a component (e.g., an electrical lead) into delivery system  200 . In such implementations, handle  300  may be configured to move from an advanced position  4200  to a retracted position  4202  to facilitate the reload of the component (e.g., the electrical lead). 
     In some implementations, handle  300  may include a dock  4204  configured to engage an alignment block coupled with the component (e.g., electrical lead) such that, responsive to handle  300  moving from advanced position  4200  to retracted position  4202 , the engagement between dock  4204  and the alignment block draws the component into delivery system  200  to reload delivery system  200 . As a non-limiting example using the implementation of component advancer  302  shown in  FIG.  13 - 14   , once the alignment block and electrical lead are properly seated within dock  4204 , handle  300  may be re-cocked (e.g., moved from position  4200  to position  4202 ), which draws distal portion  1602  of electrical lead  1600  into delivery system  200  and closes insertion tips  304 ,  306  ( FIG.  3   ). 
     In some implementations, dock  4204  may comprise one or more alignment and/or locking protrusions  4206  (the example in  FIG.  42    illustrates two protrusions  4206 ) located on a portion  4208  of handle  300  toward component advancer  302 . Locking protrusions  4206  may have a “U” shaped channel configured to receive a wire portion (e.g., part of proximal portion  1606 ) of an electrical lead  1600  ( FIG.  16   ). Locking protrusions  4206  may have a spacing  4210  that corresponds to a size of an alignment block on the wire portion of electrical lead  1600  and allows the alignment block to fit between locking protrusions  4206  (with the wire portions resting in the “U” shaped channels of locking protrusions  4206 ). 
       FIG.  43    illustrates an example of an alignment block  4300  coupled to proximal portion  1606  of an electrical lead  1600 . Alignment block  4300  may have a cylindrical shape, for example, with a length matching spacing  4210  configured to fit between locking protrusions  4206  shown in  FIG.  42   . 
     Returning to  FIG.  42   , in some implementations, handle  300  may include an alignment surface  4220  configured to receive the proximal portion  1606  ( FIG.  43   ) of electrical lead  1600  ( FIG.  16   ) such that, responsive to handle  300  moving from the advanced position to the retracted position, the component is drawn into delivery system  200  to reload delivery system  200 . In some implementations, alignment surface  4220  may be the same as surface  4208 , but without locking protrusions  4206 . In some implementations, an operator may hold proximal portion  1606  against alignment surface  4220 , within a retention block  4206 , with finger pressure while handle  300  moves from advanced position  4200  to retracted position  4202 , for example. In some implementations, the alignment block  4300  may not be utilized. 
       FIGS.  44 A- 52    illustrate an exemplary system and method for utilizing an insertion sheath while inserting an implantable lead into a patient. This method may be used with the splitting lead embodiments of the present disclosure and thus some element references will be made to the embodiments of a splitting lead depicted in  FIGS.  41 A-D  and the associated delivery systems in  FIGS.  30 A /B. 
     An advantage of the insertion sheath system includes having an “open” delivery tool insertion tip  4110 , as shown in  FIG.  46   , to facilitate the loading of a lead into the delivery tool (see open area  4630 ) but then a more closed off insertion tip during lead delivery when the insertion tip is partially covered by an insertion sheath (see the more closed off area  4930  in  FIG.  49   ). When the tip is more closed off during delivery, the deploying lead is better guided into the deployment ramps and any bulging of the lead above the ramps is constrained and avoided. The following descriptions for  FIGS.  44 A- 52    disclose additional features of and methods of use for the insertion sheath. 
       FIG.  44 A  illustrates an exemplary insertion dilator  4410  for inserting an exemplary insertion sheath  4420  into a patient. The insertion sheath  4420  can be a sufficiently long tube to extend through the patient&#39;s skin  4402  and subsequent tissue layers (e.g., subcutaneous fascia  4404  and endothoracic fascia  4406 ) to reach a desired depth such as the anterior mediastinum. The insertion sheath body  4422  can have a hollow interior for receiving various components, such as an insertion dilator  4410  and also the insertion tip  4110  of a lead delivery tool. 
     The depicted insertion dilator  4410  can be utilized with insertion sheath  4420 . When inserted into insertion sheath, the insertion dilator can extend out from the distal end  4430  of the insertion sheath such that a pointed end  4412  of the insertion dilator can act to separate patient tissue and penetrate the endothoracic fascia for the insertion sheath. Also, the insertion dilator can have an insertion dilator stopping foot  4414  that extends laterally from insertion dilator body  4416 . The insertion dilator stopping foot can engage the insertion sheath (e.g., at insertion sheath hub  4440  extending laterally from insertion sheath body  4422  at a proximal end of the insertion sheath  4420 ) when a user pushes the insertion dilator and thereby pushes the insertion sheath into the patient. The insertion dilator body may also have a handle  4418  for gripping by the user. In other embodiments, rather than including a handle, the insertion dilator may be connected to another device (e.g., a robotic medical device) that would push the insertion dilator into the patient. 
     Features are depicted in  FIG.  44 A  showing that the insertion dilator has penetrated the patient&#39;s skin and pushed the insertion sheath through the skin until it stopped at a particular depth where an insertion sheath stopping foot  4450  extending laterally from the insertion sheath body halts advancement at a particular location (e.g., abutting the subcutaneous fascia). The insertion sheath and its stopping foot are configured to result in the insertion tip of a delivery system inserted into the sheath being positioned at a particular depth within the patient (e.g., proximate the pericardium). 
     The present disclosure describes numerous devices that can be provided and/or used together to deliver and secure leads in a patient. In some embodiments, any combination of the disclosed devices can be provided in the form of a kit. For example, in some embodiments, a kit can contain a delivery system, insertion sheath, and an insertion dilator. In some embodiments, a kit can contain a delivery system and a dilator cap. In other embodiments, a kit can contain a delivery system, insertion sheath, an insertion dilator, a lead, and an anchor cap. It is contemplated that any of the particular delivery systems, insertion sheaths, insertion dilators, dilator caps, leads or anchor caps disclosed herein could be provided in the disclosed kits. 
       FIGS.  44 B and  44 C  illustrate an exemplary use and structure of a puncture tip  4460  for an insertion dilator  4410 . In some embodiments, the insertion dilator  4410  can include a puncture tip  4460  configured to extend distally from the pointed end  4412  of the insertion dilator  4410 , which can be used to create an initial puncture in biological tissues  4470 , through which the comparatively larger pointed end  4412  of the insertion dilator  4410  can follow. In various embodiments, the puncture tip  4460  can be fixed or can be retractable into the insertion dilator  4410  as shown in  FIG.  44 B . 
     In use, depressing an actuator can cause a retracted puncture tip  4460  to extend distally from the pointed end of the insertion dilator  4410  to create the initial puncture. Insertion dilator  4410  can include a button  4480  that causes advancement of the puncture tip  4460  from the pointed end  4412  of the insertion dilator  4410 . The insertion dilator  4410  can penetrate until it abuts a particular tissue layer (e.g., the endothoracic fascia or any other tissue layer that may have increased resistance to the insertion dilator  4410 ). For example, a method of use can include puncturing the endothoracic fascia with the puncture tip  4460  extending distally from the pointed end of the insertion dilator  4410 . The insertion dilator  4410  can then advance through the punctured endothoracic fascia. 
     In retractable embodiments, the insertion dilator  4410  can include a spring-actuated retraction mechanism having a spring  4490  operatively connected to the puncture tip  4460  and configured to retract the puncture tip  4460  into the insertion dilator. Button  4480  can be coupled to the spring-actuated retraction mechanism to cause the spring to compress and advance the puncture tip  4460  distally from the pointed end of the insertion dilator  4410 . By including mechanical stops or selecting a particular spring, various embodiments of the insertion dilator can be configured to limit the extent of the puncture tip extension to a predefined amount. In some embodiments, the predefined amount can be, for example, 1, 2, 3, 5, 10 mm from the pointed end. The present disclosure also contemplates fixed puncture tip embodiments (i.e., not retractable) having the same predefined extension, due to the length of the puncture tip itself. 
       FIG.  44 D  illustrates an exemplary recessed button for the insertion dilator  4410 . In some embodiments, button  4480  can be recessed into a handle  4418  of insertion dilator  4410 . Such a button can be recessed, for example, 3, 5, 7, 9 mm, etc., from a top edge  4419  of handle  4418  so that a user must actively extend into the recess to actuate button  4480  to cause the puncturing with the puncture tip as described above. 
     In other embodiments, the insertion dilator  4410  can be configured to have exchangeable ends. For example, the pointed end can be removed and replaced with a different end having a puncture tip, or a blunt tip. The insertion dilator  4410  can be configured for exchangeable ends for example with screw threads, magnets, etc. 
       FIG.  44 E  illustrates a delivery system  4400 E with an exemplary dilator cap  4410 E. In an alternative embodiment, instead of using a dilator with an insertion sheath (as in  FIG.  44 A ), a separate dilator cap can instead be used. The dilator cap can be placed over the distal end of a delivery system and can be pressed into a patient to separate tissue and create a hole for lead delivery. Once the hole in the tissue is created, the delivery system with cap can be withdrawn, the dilator cap can be removed, and the delivery system (loaded with a lead) can be inserted into the hole to deploy the lead. 
     The dilator cap  4410 E can be utilized with any of the disclosed delivery systems. For example, in various embodiments, a delivery system can have a channel  500  between first and second insertion tips  304 ,  306  (as in delivery system  200  of  FIG.  5   ), a unitary insertion tip  900  with a distal orifice  908  (as in delivery system  200  of  FIG.  9 B ), an insertion tip  4110  with an opening for loading and deploying a splitting lead  3010  (as in delivery system  3000  in  FIGS.  41 A-C , etc.). Thus, in general (though the terminology may vary slightly with the embodiment), a delivery system  4400 E can have an insertion tip  4430 E configured to be loaded with a lead and configured to deploy the lead through a distal opening  4420 E in the insertion tip. 
     Dilator cap  4410 E can be configured to fit over the insertion tip  4430 E and cover the distal opening  4420 E in the insertion tip  4430 E. In some embodiments, dilator cap  4410 E can include a tissue-separating portion  4412 E that is wedge-shaped. It can be seen from  FIG.  44 E  that the dilator cap can be shaped to compliment a shape of the delivery system to engage the delivery system  4400 E for advancing the dilator cap  4410 E. The dilator cap can also include a shoulder  4414 E configured to engage the delivery system for advancing the dilator cap. Thus, by pushing down on delivery system  4400 E, it engages shoulder  4414 E and causes advancement of dilator cap  4410 E into the patient tissue while protecting the distal opening  4420 E. 
       FIG.  45    illustrates the insertion sheath  4420  placed in the patient at the appropriate location and the insertion dilator removed. As shown, the insertion sheath stops where insertion sheath stopping foot  4450  meets subcutaneous fascia  4404 . There can be a portion of the insertion sheath that extends into the patient from the subcutaneous fascia to slightly beyond the endothoracic fascia  4406  into the anterior mediastinum, which may be desired location of lead deployment. The insertion sheath can also include an insertion sheath hub  4440  that may house other features of the insertion sheath. For example, the insertion sheath hub can contain a protection valve configured to close around the delivery system to reduce or prevent air exchange through the hollow interior of the insertion sheath into/from the anterior mediastinum. The valve may be comprised of separating flaps or a membrane that can be penetrated by the delivery tool during insertion, but again come together when the delivery tool is removed to prevent air exchange through the hollow interior. 
     Once the insertion sheath  4420  is in place, lead delivery can commence.  FIG.  46    illustrates exemplary features of a lead delivery system that facilitate loading a lead into the insertion tip. The distal end of the insertion tip  4110  can have two portions, an enclosed portion  4610  that constrains a lead and an open portion  4620  that includes ramp(s) ( 4120 ,  4130 ) that act to aid and deployment of the lead. The longitudinal distance where the lead is no longer constrained on all sides is referred to herein as the “window”  4630 . As shown, with a larger window, it is easier to load the splitting lead  3010  (shown slightly protruding from within the insertion tip) because there is less friction between the splitting lead and the walls of the insertion tip. In this exemplary embodiment, the window  4630  can be larger than the longitudinal (vertical) extent of the ramp(s). 
       FIG.  47 A  illustrates a delivery system inserted into the insertion sheath. With the insertion sheath  4420  properly placed in the patient, delivery system  3000  can be inserted into the insertion sheath to reach the desired location in the patient. As shown, the delivery system  3000  can have a flat portion  3002  that abuts the proximal end of the insertion sheath causing a natural stop, with the insertion tip slightly extending beyond the distal end  4430  of the insertion sheath. 
       FIG.  47 B  illustrates exemplary embodiments of insertion sheaths that can act, given the selected dimensions of the sheath components, to place the delivery system insertion tip at the proper location for deployment of a lead. For example, the insertion sheath stopping foot  4450  can be located farther up insertion sheath shaft  4710  (as shown on sheath  4720 B). This will cause the delivery system tip to exit the sheath at a deeper location into the patient, as shown, but can allow the length of the insertion sheath shaft to remain unchanged. In another implementation, the length of insertion sheath shaft  4710  that is below the stopping foot  4450  is increased for greater insertion depth, but the length of the shaft above the stopping foot can remain the same. In this implementation, the insertion sheath used for deeper implantation will end up having a longer shaft than sheath  4420 . The kits described herein as including a sheath could thus alternatively be provided with multiple sheaths configured to result in multiple implantation depths. 
       FIG.  48    illustrates an exemplary deployment of a splitting lead. While the present disclosure contemplates that the delivery systems herein can advance any of the disclosed leads through an insertion tip,  FIG.  48    depicts one example of advancing a splitting lead. The delivery system  3000  can be activated by a user (e.g., by squeezing a handle, pointer, etc.) to advance the splitting lead  3010  through the insertion tip  4110 . As shown in FIG.  48 , and also described in previous embodiments, the splitting lead can then extend from the insertion tip with the sub-portions  3040  of the splitting lead separating in lateral directions into the patient. 
       FIG.  49    illustrates the insertion sheath creating a reduced window that improves deployment of the splitting lead. When advancing the splitting lead into tissues, the tissues may push back against the lead and cause unwanted or premature splitting of the lead and/or the splitting lead to “bulge” out prior to interaction with the ramps that are intended to guide proper lead deployment. In the expanded view of  FIG.  49   , the insertion sheath  4420  acts to reduce the window  4930 , thereby forcing deployment of the lead to be at the proper location (e.g., starting the splitting at the start of the ramps rather than before them). It can be seen in the figure that the insertion sheath can be configured to decrease the size of the window because window  4930  now has a smaller distance between the distal end of insertion tip  4110  and the distal end of the insertion sheath  4420  (as contrasted with the larger window  4630  in  FIG.  46   ). 
     In another embodiment, the enclosed portion of the insertion tip itself (see  FIG.  46   ) can be configured to be extended distally, closer to the ramps, to make the window equivalent to that shown in  FIG.  49   . Such an embodiment may optionally be utilized without use of the insertion sheath. 
     In an alternative method for decreasing the size of a large lead loading window in order to prevent lead bulging during deployment, some embodiments can include (e.g., as part of a kit with a delivery system), a ring having a hollow interior shaped to receive the distal end of a delivery system insertion tip. The ring can be configured to generally constrain the lead in a manner similar to that of the insertion sheath, without the need for an insertion sheath. In particular, some such embodiments can have the ring being of a length that a distal end of the ring meets the beginning of ramps in an insertion tip. Examples of such lengths can include 15, 17, 19, 21, or 23 mm or as needed to abut the delivery system (e.g., at flat portion  3002 ) and have the distal end be at a given location relative to the ramps. In some embodiments, the ring can have a narrowing along an inner distal edge to provide a smoother transition for the lead as it exits the ring. 
     The sheaths and rings disclosed herein can be used both with delivery systems delivering splitting leads and other delivery systems. 
       FIG.  50    illustrates removal of the delivery system and insertion tip. With splitting lead  3010  deployed, the delivery system  3000  and insertion tip  4110  can be withdrawn. With the insertion tip no longer between the splitting lead and the insertion sheath, the protection valve within the sheath can then seal against the lead body to continue to provide protection against air exchange. 
       FIGS.  51 - 53    illustrate removal of an insertion sheath embodiment having separating portions. At this point in the delivery process, the insertion sheath  4420  can be removed from the patient. However, to reduce the contact between the insertion sheath and the lead  3010 , some embodiments of the insertion sheath can be at least partially separable ( FIG.  51   ) to effectively loosen the sheath contact around the splitting lead so as not to drag on or disturb the splitting lead when the insertion sheath is withdrawn ( FIG.  52   ). In one embodiment, the insertion sheath can be configured to at least partially separate (e.g., crack open) along at least a portion of its length to facilitate removal over the lead. Examples of such separable portions can include at least the portion including insertion sheath hub  4440  containing the protective valve (to prevent the valve from grabbing onto the lead body during sheath removal). Other embodiments may also include portions of the lead body and/or the insertion sheath stopping foot being separable as well. In another embodiment, portions of the insertion sheath (as above) can be configured to fully separate into two or more pieces which can then be individually withdrawn around the lead body (e.g., by pulling the pieces somewhat to the sides and withdrawing). With the insertion sheath fully withdrawn ( FIG.  53   ), the splitting lead  3010  can be prepared for use. In some embodiments, a lead anchor such as sutures or other methods of fixation can be utilized to fixate the splitting lead to the patient&#39;s tissues (e.g., to the subcutaneous fascia). 
       FIG.  54    illustrates a lead with suture holes  5460  for securing the lead to tissue. In some embodiments, suture holes  5460  may be located in a proximal part  5430  of the distal portion  5410  of lead (i.e., the portion that does not travel in a different direction during implantation). A physician may tie sutures through a patient&#39;s tissues and suture holes  5460  in order to better fix the orientation of the distal portion of the lead at implantation. The sutures may be tied to intercostal muscle, skin, or any other portion of the patient suitable for securing the lead. While one exemplary configuration is depicted in  FIG.  54   , any number and/or combination of suture holes and suture hole locations can be included in any of the lead embodiments detailed throughout the present disclosure. For example, such suture holes may be utilized with splitting leads as well. Furthermore, rather than complete suture holes, one or more grooves or notches may be located on the proximal part  5430  of the distal portion of the lead. Such grooves or notches provide indentations that may aid in securing of the lead to the patient&#39;s tissue. 
       FIG.  55    illustrates a lead anchor  5500  for securing a lead. Lead anchor  5500  can be configured to slide over and securely fit on an elongated lead body (e.g., as in  FIGS.  33 A,  54   , etc.). For example, the lead anchor may slide over a “proximal part” of the distal end of an elongated lead body as shown as part  3320 A in  FIG.  33 A and  5430    in  FIG.  54   . Lead anchor  5500  can be flexible/elastic plastic, rubber, or other deformable material that can stretch to cover a portion of the lead and remain secured when released. An exterior  5510  of lead anchor  5500  can have fixation features  5520  for facilitating fixation to patient tissue. In some embodiments, fixation features  5520  of lead anchor  5500  can include grooves, notches, or holes that facilitate suturing to biological tissue, with examples of grooves/notches depicted in  FIG.  55   . 
       FIG.  56 A  illustrates a lead anchor insertion tool  5600 A for pushing a lead anchor onto a lead. Lead anchor insertion tool  5600 A can include a body  5610 A having a bore  5620 A extending longitudinally through body  5610 A and shaped to accept a lead anchor (e.g., lead anchor  5500 ). 
     In some embodiments, the lead anchor insertion tool  5600 A can have a textured surface  5652 A on a surface  5650 A of its bore. The textured surface can be complimentary to an exterior of the lead anchor (e.g., have a similar groove/notch pattern) or can have a different texture such as crossed scoring. Lead anchor insertion tool  5600 A can include a handle  5640 A extending in a lateral direction from the body to aid in pushing the lead anchor onto the lead. 
     Also, lead anchor insertion tool&#39;s body  5610 A can be configured to open along a longitudinal split  5630 A and allow the lead anchor to be placed within the body. Such an opening can be configured by lead anchor insertion tool  5600 A being thin and flexible in places or having an opening along a hinge, etc. In some embodiments, lead anchor insertion tool  5600 A can have a locking clasp  5660 A to hold the lead anchor insertion tool  5600 A in a closed configuration. Locking clasp  5660 A can include a male locking portion  5662 A formed along a first half of longitudinal split  5630 A and female locking portion  5664 A formed along on a second half of the longitudinal split. Other locking mechanisms can include magnets, screws, etc. 
     In some embodiments, lead anchor insertion tool  5600  can alternatively be configured to grab onto a lead having an integrated lead anchor (described below) to further position the lead in the patient. 
       FIG.  56 B  illustrates a lead anchor insertion system  5600 B for inserting a lead anchor onto a lead. The lead anchor insertion system  5600 B can include a lead anchor  5630 B configured to securely fit on a proximal part of a distal portion of an electrical lead (e.g., part  3320 A in  FIG.  33 A or  5430    in  FIG.  54   ). Lead anchor  5630 B can have an exterior  5631 B having fixation features  5632 B for facilitating fixation to patient tissue (similar to the lead anchor embodiment shown in  FIG.  55   ). Lead anchor  5630 B can also have split segments  5633 B to facilitate being placed over a lead anchor delivery tube  5640 B. 
     Lead anchor insertion system  5600 B can also include a lead anchor delivery tube  5640 B with a body  5642 B having a distal end  5641 B and proximal end  5643 B. Body  5642 B can have an outer diameter configured to stretch the lead anchor  5630 B (i.e., be larger than the inner diameter of lead anchor  5630 B in its natural state) and an inner diameter configured to receive an electrical lead (i.e., a diameter large enough for a lead to move freely through the tube body). In some embodiments, the inner diameter of the lead anchor delivery tube  5640 B can be further configured to receive a lead connector that may be of a larger diameter than the electrical lead (for example, a DF4 connector). Lead anchor delivery tube  5640 B can also include a handle  5644 B at proximal end  5643 B. In some embodiments, handle  5644 B can be removable to allow a lead anchor pushing tool  5660 B to slide over proximal end  5643 B of the lead anchor delivery tube  5640 B. Lead anchor delivery tube  5640 B can be comprised of metal, polymer, a combination of materials, or essentially any material having the appropriate stiffness to perform the functions of the tube as described herein. One exemplary material for the tube is hypotubing. 
     Lead anchor insertion system  5600 B can further include a lead anchor pushing tool  5660 B with body  5662 B. Body  5662 B can have an outer diameter configured to fit within an incision and abut biological tissue of a patient (for example, a patient&#39;s ribs or fascia). Body  5662 B can also include two different-sized bores: a bore at a distal end  5664 B of body  5662 B having a first diameter configured to receive a lead anchor  5630 B when stretched over lead anchor delivery tube  5640 B, and a bore at a proximal end  5666 B of body  5662 B having a second diameter, smaller than the first diameter and configured to receive the lead anchor delivery tube  5640 B ( FIG.  56 D  depicts these two different-sized bores). The lead anchor pushing tool  5660 B can also include a handle  5668 B at distal end  5664 B of body  5662 B. 
     While the depicted embodiments are shown and described as having a circular cross section, the present disclosure contemplates that other cross-sectional shapes can be utilized, for example, square, rectangular, etc. As such, the term “diameter” should be interpreted as generally referring to a relevant dimension without requiring that any given embodiment be a circle. For example, a rectangular cross-section might have a second width instead of a second diameter, but still be shaped to receive a lead anchor delivery tube  5640 B. 
     In various embodiments, lead anchor insertion system  5600 B can be provided as a kit that can include any combination of the components described herein. In one example, the kit may include a lead anchor delivery tube, a lead anchor pushing tool and lead anchor itself. In another example, the kit may include a lead anchor delivery to and a lead anchor pushing tool. 
       FIG.  56 C  illustrates an exemplary method of using the lead anchor insertion system to place a lead anchor onto a lead (e.g., any of the leads described herein), after the lead has been inserted into a patient, in order to aid in securing the lead to patient tissue. 
     Some methods can include first placing a lead anchor pushing tool  5660 B over a lead anchor delivery tube  5640 B. The lead anchor pushing tool  5660 B can be placed over the lead anchor delivery tube  5640 B in a number of ways. For example, the lead anchor pushing tool  5660 B can be slid over distal end  5641 B of the lead anchor delivery tube  5640 B in a backwards manner, prior to the lead anchor  5630 B being slid onto the lead anchor delivery tube  5640 B. In some embodiments, tube handle  5644 B can be a removable screw-on handle. As such, without handle  5644 B in place, the method of placing the lead anchor pushing tool  5660 B over a lead anchor delivery tube  5640 B can also include sliding the lead anchor pushing tool  5660 B over a proximal end  5643 B of the lead anchor delivery tube  5640 B. Then, after advancing the lead anchor pushing tool  5660 B sufficiently along lead anchor delivery tube  5640 B, handle  5644 B can be screwed onto proximal end  5643 B of lead anchor delivery tube  5640 B. In other embodiments, placing the lead anchor pushing tool  5660 B over a lead anchor delivery tube  5640 B can include folding the lead anchor pushing tool  5660 B over the lead anchor delivery tube  5640 B (in embodiments where there is a split along body  5662 B of the lead anchor pushing tool  5660 B). 
     At  5610 C, a lead anchor  5630 B can be slid onto distal end  5641 B of the lead anchor delivery tube  5640 B. In some embodiments, the lead anchor  5630 B may be elastic, accordingly, sliding lead anchor  5630 B onto the distal end  5641 B of the lead anchor delivery tube  5640 B can include stretching the lead anchor  5630 B over the lead anchor delivery tube  5640 B.  5610 C also illustrates that sliding the lead anchor  5630 B onto distal end  5641 B of the lead anchor delivery tube  5640 B can include sliding the lead anchor  5630 B until a distal edge  5636 B of the lead anchor  5630 B is flush with a distal edge  5646 B of the lead anchor delivery tube  5640 B. In other embodiments, the lead anchor  5630 B is pushed over the lead anchor delivery tube  5640 B until the distal end of the lead anchor delivery tube  5640 B abuts an internal feature of the lead anchor  5630 B, thereby preventing further advancement and properly aligning the lead anchor  5630 B onto the lead anchor delivery tube  5640 B. 
     At  5620 C, the lead anchor delivery tube  5640 B can be slid over a proximal part  3320  of a distal portion of the electrical lead  3010 . The proximal part  3320  of the distal portion of electrical lead  3010  can be, for example, a portion that extends at least partially through patient tissues. Examples of proximal parts are shown in  FIG.  33    as proximal part  3320  of splitting lead  3010 , in  FIG.  54    as proximal part  5430  of distal portion  5410  of a lead, etc. In some embodiments, lead anchor delivery tube  5640 B can first be positioned partially over proximal part  3320  (as shown in  5630 C). In another embodiment, lead anchor delivery tube  5640 B can be positioned as distally as possible down proximal part  3320 , for example, nearly to where electrical lead  3010  is depicted as splitting. In other embodiments, lead anchor delivery tube  5640 B can first be positioned proximally to, but not over, proximal part  3320 . In one embodiment, the distal end  5641 B of the lead anchor delivery tube  5640 B is sized and shaped such that it engages top shoulder  3321  of the proximal part  3320 . By matching the size and shape of the distal end  5641 B of the lead anchor delivery tube  5640 B to the size and shape of the proximal part  3320 , lead anchor  5630 B can be easily slid from the lead anchor delivery tube  5640 B onto proximal part  3320 . 
     An electrical lead  3010  can have wires or cables contained within a longer flexible lead body (shown in  5620 C by the narrower portion extending from electrical lead  3010  into lead anchor delivery tube  5640 B) for connecting electrodes to a pulse generator and a pulse generator connector may be included at a proximal end of the wires or cables to facilitate this connection. Accordingly, in some embodiments, the method can also include sliding lead anchor delivery tube  5640 B over a pulse generator connector. 
     At  5630 C, the lead anchor pushing tool  5660 B can be slid towards lead anchor  5630 B until it engages lead anchor  5630 B (as further illustrated in  FIG.  56 D ). 
     Some embodiments can also include using the lead anchor pushing tool  5660 B to move the lead anchor  5630 B further distally until the lead anchor reaches a desired position. The desired position is understood to be a location determined to be appropriate for properly securing the electrical lead  3010  to the patient&#39;s biological tissues. One example of a desired position is shown in in  FIG.  56 C  where the lead anchor  5630 B is mostly down the distal part  3320  of electrical lead  3010 . Some embodiments can include pushing the lead anchor pushing tool  5660 B until an outer diameter of body  5662 B of the lead anchor pushing tool  5660 B abuts biological tissue of the patient. For example, abutting the patient&#39;s ribs or fascia can stop advancement of the lead anchor pushing tool  5660 B to avoid over-insertion. 
     At  5640 C, lead anchor pushing tool  5660 B can be held in place while withdrawing the lead anchor delivery tube  5640 B such that the lead anchor  5630 B is left securely fit on electrical lead  3010  at the desired position. 
     At  5650 C, lead anchor delivery tube  5640 B has been withdrawn from lead anchor  5630 B, leaving it securely fit around electrical lead  3010  as shown. 
     Embodiments of the method described with reference to  FIG.  56 C  can have some steps performed in a different order than described above. Accordingly, the disclosed example should not be considered exclusive of other similar methods or equivalent implementations. 
       FIG.  56 D  illustrates cross-sectional views of an exemplary lead anchor pushing tool (top) and an exemplary lead anchor insertion system including a tube and lead anchor (bottom). Lead anchor pushing tool  5660 B is depicted on the top of the diagram to show its outer diameter  5666 C, first diameter  5662 C and second diameter  5664 C. As previously mentioned, outer diameter  5666 C can be selected to prevent over-insertion, for example, by being sufficiently large so as to not fit between patient ribs, first diameter  5662 C can be selected to receive a lead anchor  5630 B when stretched over a lead anchor delivery tube  5640 B, and second diameter  5664 C can be selected to receive the lead anchor delivery tube  5640 B. The combination of diameter  5662 C and length  5662 D are intended to contain the proximal portion of the lead anchor  5630 B, thereby preventing lead anchor  5630 B from bulging outwards during advancement over the electrical lead  3010 . Furthermore, if the design of the proximal portion of lead anchor  5630 B contains split segments  5633 B, as can be seen in  FIG.  56 B , the combination of the diameter  5662 C and length  5662 D providing for containment of split segments  5633 B can allow pushing pressure to be applied to the proximal end of the lead anchor  5630 B. 
     In exemplary embodiments, the outer diameter  5666 C can be 12-14 mm or sized large enough to abut ribs and not pass through a hole in the endothoracic fascia created by a delivery tool. The first diameter  5662 C can be 8-12 mm or have its smallest value selected based on dimensions of the lead anchor  5630 B. The second diameter  5664 C can be such that lead anchor delivery tube  5640 B can slide through it, with lead anchor delivery tube  5640 B sized to allow it to engage proximal part  3320  and to slide over wires or cables of the electrical lead  3010  (e.g., greater than 3 mm or greater than 3.2 mm). In other exemplary embodiments, length  5662 D can be chosen to allow different amounts of the lead anchor  5630 B to be inserted into the lead anchor pushing tool  5660 B. For example, if 25% is to be inserted then approximately 10 mm, if 50%, approximately 20 mm, etc. The split segments  5633 B of the lead anchor  5630 B can be, for example, 15 mm, 20 mm, 25 mm, etc. in length. 
     The bottom diagram of  FIG.  56 D  illustrates an exemplary engagement between the lead anchor pushing tool  5660 B and the lead anchor  5630 B. In this diagram, it can be seen that the second diameter  5564 C can be configured to provide a pushing surface  5663 C sufficient for pushing for lead anchor  5630 B. Pushing surface  5663 C can be formed by second diameter  5664 C being, for example, 0.5 mm, 1 mm, 2 mm, 4 mm, etc., smaller than the first diameter. As another example, second diameter  5664 C can be smaller than the first diameter  5662 C by an amount equal to twice a thickness of the lead anchor  5630 B (i.e., the second diameter being the same as the inner diameter of lead anchor  5630 B). Exemplary lead anchor thicknesses include 1.3 mm, 1.5 mm, or 1.7 mm. 
       FIG.  57 A  illustrates a lead  5700 A with indentations  5710 A for securing the lead to tissue. In the depicted embodiment, the indentations  5710 A can be formed in the lead itself in order to create an integrated lead anchor. In some embodiments, a method of securing such a lead can include inserting an electrical lead (e.g., having a distal portion with electrode(s) configured to generate therapeutic energy for biological tissue of the patient), where a proximal part  5712 A of the distal portion can have grooves or notches (e.g., indentations  5710 A). The method can also include securing the lead to patient tissue by suturing around the lead through the grooves or notches and into the biological tissue. As with other embodiments herein, the lead can also include a proximal portion coupled to the distal portion and configured to engage a controller configured to cause the electrodes to generate therapeutic energy. 
       FIG.  57 B  illustrates lead  5700 A and an anchor cap  5720 B. In some embodiments, to fill any empty space in the patient&#39;s tissue, an anchor cap  5720 B can be utilized. A method of using such an anchor cap can include sliding an anchor cap  5720 B over the distal portion of lead  5700 A until a cap head  5722 B of the anchor cap  5720 B covers an opening in the patient tissue smaller than a width of the cap head  5722 B. In some embodiments, the method can also include securing the cap head  5722 B to the patient tissue utilizing one or more holes or notches  5724 B in the cap head  5722 B. In some embodiments, such an anchor cap can also be used with any of the leads disclosed herein, such as ones without indentations  5710 A. Structurally, anchor cap can include an aperture  5726 B having a shape corresponding to a cross-section of the proximal part of the lead over which the anchor cap is configured to be placed. The anchor cap can include a cap body  5723 B and a cap head  5722 B that extends laterally beyond the cap body. Anchor cap  5720 A can also include one or more holes or notches  5724 B on the cap head to facilitate suturing to patient tissue and/or to the lead. 
     In the following, further features, characteristics, and exemplary technical solutions of the present disclosure will be described in terms of items that may be optionally claimed in any combination: 
     Items 1-73 intentionally omitted. 
     Item 74: A method comprising: inserting an insertion dilator into an insertion sheath such that the insertion dilator extends out from a distal end of an insertion sheath; penetrating patient skin with the insertion dilator to push the insertion sheath through the skin to reach a particular depth; removing the insertion dilator from the insertion sheath; inserting a delivery system into the insertion sheath; deploying a lead by advancing the lead through an insertion tip of the delivery system. 
     Item 75: The method of item 74, wherein the insertion dilator penetrates until the insertion dilator abuts the endothoracic fascia, the method further comprising: puncturing the endothoracic fascia with a puncture tip extending distally from a pointed end of the insertion dilator; and advancing the insertion dilator through the punctured endothoracic fascia. 
     Item 76: The method as in any one of the preceding items, further comprising depressing an actuator to cause a retracted puncture tip to extend distally from the pointed end of the insertion dilator. 
     Item 77: A method comprising: inserting an electrical lead comprising: a proximal portion configured to engage a controller, the controller configured to cause one or more electrodes to generate therapeutic energy; and a distal portion coupled to the proximal portion, the distal portion comprising: one or more electrodes that are configured to generate the therapeutic energy for biological tissue of a patient; and one or more grooves or notches in a proximal part of the distal portion; and securing the lead to patient tissue by suturing around the lead through the one or more grooves or notches and into the biological tissue. 
     Item 78: The method of item 77, further comprising sliding an anchor cap over the distal portion. 
     Item 79: The method as in any one of the preceding items, further comprising securing a cap head to the biological tissue utilizing one or more holes or notches in the cap head. 
     Item 80: An insertion sheath configured to receive a delivery system and facilitate positioning of an insertion tip of the delivery system within a patient, the insertion tip including a window through which a lead can be loaded, the insertion sheath comprising: an insertion sheath body having a hollow interior shaped to receive the delivery system; an insertion sheath hub extending laterally from the insertion sheath body at a proximal end of the insertion sheath; and an insertion sheath stopping foot extending laterally from the insertion sheath body. 
     Item 81: The insertion sheath of item 80, wherein the insertion sheath and the insertion sheath stopping foot are configured to result in the insertion tip being positioned at a particular depth within the patient. 
     Item 82: The insertion sheath as in any one of the preceding items, wherein the particular depth is proximate the pericardium. 
     Item 83: The insertion sheath as in any one of the preceding items, wherein the insertion sheath is further configured to decrease a size of the window. 
     Item 84: The insertion sheath as in any one of the preceding items, the insertion sheath hub comprising a valve configured to close around the delivery system to reduce air exchange through the hollow interior of the insertion sheath. 
     Item 85: The insertion sheath as in any one of the preceding items, further comprising a separable portion that is at least partially separable along at least a portion of a length of the insertion sheath. 
     Item 86: An insertion dilator configured to separate patient tissue and to be used with an insertion sheath, the insertion dilator comprising: an insertion dilator body having a handle, an insertion dilator stopping foot extending laterally and configured to engage the insertion sheath, and having a length such that a portion of the insertion dilator body extends beyond the insertion sheath; and a pointed end configured to separate the patient tissue. 
     Item 87: The insertion sheath of item 86, further comprising a puncture tip configured to extend distally from the pointed end of the insertion dilator. 
     Item 88: The insertion sheath as in any one of the preceding items, wherein the insertion dilator is configured to cause advancement of the puncture tip up to a predefined amount from the pointed end of the insertion dilator. 
     Item 89: The insertion sheath as in any one of the preceding items, wherein the predefined amount is 2 mm. 
     Item 90: The insertion sheath as in any one of the preceding items, further comprising a button that causes advancement of the puncture tip from the pointed end of the insertion dilator. 
     Item 91: The insertion sheath as in any one of the preceding items, wherein the button is recessed into the handle of the insertion dilator. 
     Item 92: The insertion sheath as in any one of the preceding items, wherein the puncture tip is retractable into the insertion dilator. 
     Item 93: The insertion sheath as in any one of the preceding items, further comprising a spring-actuated retraction mechanism having a spring operatively connected to the puncture tip and configured to retract the puncture tip into the insertion dilator. 
     Item 94: The insertion sheath as in any one of the preceding items, wherein the insertion dilator is configured for exchangeable ends. 
     Item 95: A kit comprising: a delivery system with an insertion tip configured to be loaded with a lead through a window, the delivery system further configured to deploy the lead through the insertion tip; an insertion sheath configured to receive the delivery system and facilitate positioning of the insertion tip of the delivery system within a patient, the insertion sheath comprising: an insertion sheath body having a hollow interior shaped to receive the delivery system; an insertion sheath hub extending laterally from the insertion sheath body at a proximal end of the insertion sheath; and an insertion sheath stopping foot extending laterally from the insertion sheath body; and an insertion dilator configured to separate patient tissue and to be used with the insertion sheath, the insertion dilator comprising: an insertion dilator body having a handle, an insertion dilator stopping foot extending laterally and configured to engage the insertion sheath, and having a length such that a portion of the insertion dilator body extends beyond the insertion sheath; and a pointed end configured to separate the patient tissue. 
     Item 96: The kit of item 95, wherein the insertion sheath and the insertion sheath stopping foot are configured to result in the insertion tip being positioned at a particular depth within the patient. 
     Item 97: The kit as in any one of the preceding items, wherein the particular depth is proximate the pericardium. 
     Item 98: The kit as in any one of the preceding items, wherein the insertion sheath is further configured to decrease a size of the window. 
     Item 99: The kit as in any one of the preceding items, the insertion sheath comprising a separable portion that is at least partially separable along at least a portion of a length of the insertion sheath. 
     Item 100: The kit as in any one of the preceding items, further comprising an anchor cap having an aperture with a shape corresponding to a cross-section of a proximal part of the lead over which the anchor cap is configured to be placed. 
     Item 101: The kit as in any one of the preceding items, the anchor cap comprising a cap body and a cap head that extends laterally beyond the cap body. 
     Item 102: The kit as in any one of the preceding items, the anchor cap comprising one or more holes or notches on the cap head to facilitate suturing to patient tissue and/or to the lead. 
     Item 103: A system comprising: a delivery system having an insertion tip configured to be loaded with a lead, the delivery system configured to deploy the lead through a distal opening in an insertion tip; and a dilator cap configured to fit over the insertion tip and cover the distal opening in the insertion tip. 
     Item 104: The system of item 103, the dilator cap comprising a tissue-separating portion that is wedge-shaped. 
     Item 105: The system as in any one of the preceding items, the dilator cap comprising a shoulder configured to engage the delivery system for advancing the dilator cap. 
     Item 106: The system as in any one of the preceding items, the dilator cap shaped to compliment a shape of the delivery system to engage the delivery system for advancing the dilator cap. 
     Item 107: A system comprising: a lead anchor configured to slide over and securely fit on an elongated lead body, an exterior of the lead anchor comprising fixation features for facilitating fixation to patient tissue. 
     Item 108: The system of item 107, wherein the fixation features of the lead anchor include one or more grooves, notches, or holes that facilitate suturing to patient tissue. 
     Item 109: A system comprising: a lead anchor insertion tool comprising a body having a bore extending longitudinally through the body and shaped to accept a lead anchor, wherein the body is configured to open along a longitudinal split and allow the lead anchor to be placed within the body. 
     Item 110: The system of item 109, the lead anchor insertion tool further comprising a handle extending in a lateral direction from the body. 
     Item 111: The system as in any one of the preceding items, the lead anchor insertion tool having a textured surface on a surface of the bore. 
     Item 112: The system as in any one of the preceding items, wherein the textured surface is complimentary to an exterior of the lead anchor. 
     Item 113: The system as in any one of the preceding items, the lead anchor insertion tool having a locking clasp comprising: a male locking portion formed along a first half of the longitudinal split; and a female locking portion formed along on a second half of the longitudinal split, the male locking portion and the female locking portion configured to hold the lead anchor insertion tool in a closed configuration. 
     Item 114: A method comprising: inserting an electrical lead comprising: a proximal portion configured to engage a controller, the controller configured to cause one or more electrodes to generate therapeutic energy; and a distal portion coupled to the proximal portion, the distal portion comprising: one or more electrodes that are configured to generate the therapeutic energy for biological tissue of a patient; and fitting a lead anchor on a proximal part of the electrical lead, an exterior of the lead anchor comprising fixation features for facilitating fixation to patient tissue; and securing the electrical lead to patient tissue by fixating the lead anchor to the patient tissue. 
     Item 115: The method as in any one of the preceding items, wherein the fixation features of the lead anchor include one or more grooves, notches, or holes that facilitate suturing to patient tissue, the method further comprising suturing the lead anchor to the patient tissue utilizing the one or more grooves, notches, or holes. 
     Item 116: An electrical lead comprising: a proximal portion configured to engage a controller, the controller configured to cause one or more electrodes to generate therapeutic energy; and a distal portion coupled to the proximal portion, the distal portion comprising: one or more electrodes that are configured to generate the therapeutic energy for biological tissue of a patient; and one or more grooves or notches in a proximal part of the distal portion. 
     Item 117: A system comprising: a lead anchor pushing tool with a body having: an outer diameter configured to fit within an incision and abut a biological tissue of a patient; a bore at a distal end of the body having a first diameter configured to receive a lead anchor when stretched over a lead anchor delivery tube; and a bore at a proximal end of the body having a second diameter, smaller than the first diameter and configured to receive the lead anchor delivery tube. 
     Item 118: The system as in any one of the preceding items, wherein the second diameter is further configured to provide a pushing surface sufficient for pushing for the lead anchor. (i.e., smaller diameter is small enough to create a pushing surface) 
     Item 119: The system as in any one of the preceding items, wherein the second diameter is 2 mm smaller than the first diameter. 
     Item 120: The system as in any one of the preceding items, wherein the second diameter is smaller than the first diameter by an amount equal to twice a thickness of a lead anchor. 
     Item 121: The system as in any one of the preceding items, wherein the biological tissue is fascia or patient ribs and the outer diameter is sufficiently large to not fit between patient ribs. 
     Item 122: The system as in any one of the preceding items, the lead anchor pushing tool further comprising a handle at the distal end of the body. 
     Item 123: The system as in any one of the preceding items, the system further comprising the lead anchor delivery tube. 
     Item 124: The system as in any one of the preceding items, wherein the lead anchor delivery tube has a body comprising: an outer diameter configured to stretch the lead anchor; and an inner diameter configured to receive an electrical lead. 
     Item 125: The system as in any one of the preceding items, wherein the inner diameter of the lead anchor delivery tube is further configured to receive a lead connector. 
     Item 126: The system as in any one of the preceding items, the lead anchor delivery tube further comprising a handle at a proximal end of the lead anchor delivery tube. 
     Item 127: The system as in any one of the preceding items, wherein the handle is removable to allow the lead anchor pushing tool to slide over a proximal end of the lead anchor delivery tube. 
     Item 128: The system as in any one of the preceding items, wherein the tube comprises hypotubing. 
     Item 129: A method comprising: inserting an electrical lead into a patient; placing a lead anchor pushing tool over a lead anchor delivery tube; sliding a lead anchor onto a distal end of the lead anchor delivery tube; sliding the lead anchor delivery tube over a proximal part of a distal portion of the electrical lead; sliding the lead anchor pushing tool towards the lead anchor until it engages the lead anchor; and holding the lead anchor pushing tool in place while withdrawing the lead anchor delivery tube such that the lead anchor is securely fit on the electrical lead at a desired position. 
     Item 130: The method as in any one of the preceding items, wherein placing the lead anchor pushing tool over a lead anchor delivery tube further comprises sliding the lead anchor pushing tool over a proximal end of the lead anchor delivery tube and screwing a handle onto the proximal end of the lead anchor delivery tube. 
     Item 131: The method as in any one of the preceding items, wherein placing the lead anchor pushing tool over a lead anchor delivery tube further comprises folding the lead anchor pushing tool over the lead anchor delivery tube via a split along a body of the lead anchor pushing tool. 
     Item 132: The method as in any one of the preceding items, wherein sliding the lead anchor onto the distal end of the lead anchor delivery tube includes stretching the lead anchor over the lead anchor delivery tube. 
     Item 133: The method as in any one of the preceding items, wherein sliding the lead anchor onto the distal end of the lead anchor delivery tube further comprises sliding the lead anchor until a distal edge of the lead anchor is flush with a distal edge of the lead anchor delivery tube. 
     Item 134: The method as in any one of the preceding items, further comprising sliding the lead anchor delivery tube over a pulse generator connector. 
     Item 135: The method as in any one of the preceding items, further comprising using the lead anchor pushing tool to move the lead anchor distally until the lead anchor reaches the desired position. 
     Item 136: The method as in any one of the preceding items, further comprising pushing the lead anchor pushing tool until an outer diameter of a body of the lead anchor pushing tool abuts a biological tissue of the patient. 
     Item 137: A kit comprising: a lead anchor configured to securely fit on a proximal part of a distal portion of an electrical lead, an exterior of the lead anchor comprising fixation features for facilitating fixation to patient tissue; a lead anchor delivery tube with a body having: an outer diameter configured to stretch the lead anchor; and an inner diameter configured to receive the electrical lead; and a lead anchor pushing tool with a body having: an outer diameter configured to fit within an incision and abut a biological tissue of a patient; a bore at a distal end of the body having a first diameter configured to receive a lead anchor when stretched over the lead anchor delivery tube; and a bore at a proximal end of the body having a second diameter, smaller than the first diameter and configured to receive the lead anchor delivery tube. 
     Item 138: An electrical lead for implantation in a patient, the electrical lead comprising: a distal portion configured to split apart into sub-portions that travel in multiple directions during implantation into the patient; and an electrode extension that increases a distance between an electrode and one or more other electrodes on the distal portion of the lead and/or facilitates contact of the electrode with patient tissue. 
     Item 139: The electrical lead as in any one of the preceding items, further comprising concavities shaped to receive the electrode extension. 
     Item 140: The electrical lead as in any one of the preceding items, further comprising a protective collar that at least partially surrounds the electrode extension. 
     Item 141: The electrical lead as in any one of the preceding items, further comprising concavities shaped to receive the protective collar. 
     Item 142: The electrical lead as in any one of the preceding items, wherein the protective collar has a protective collar stopping foot, and a distance between a distal face of the protective collar stopping foot and a tip of the electrode is configured to minimize the likelihood of tissue perforation. 
     Item 143: The electrical lead as in any one of the preceding items, wherein the protective collar includes an anti-inflammatory substance. 
     Item 144: The electrical lead as in any one of the preceding items, wherein the protective collar is configured to release the anti-inflammatory substance on a time-delayed basis. 
     Item 145: A method comprising utilization of any one of the preceding Items. 
     Item 146: A system comprising: an apparatus described in any one of the preceding Items. 
     Item 147: A computer program product comprising a non-transitory machine-readable medium storing instructions which, when executed by the at least one programmable processor, cause the at least one programmable processor to perform operations causing a method utilizing an apparatus as described in any one of the preceding items. 
     One or more aspects or features of the subject matter described herein can be realized in digital electronic circuitry, integrated circuitry, specially designed application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) computer hardware, firmware, software, and/or combinations thereof. These various aspects or features can include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. The programmable system or computing system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. 
     These computer programs, which can also be referred to programs, software, software applications, applications, components, or code, include machine instructions for a programmable processor, and can be implemented in a high-level procedural language, an object-oriented programming language, a functional programming language, a logical programming language, and/or in assembly/machine language. As used herein, the term “machine-readable medium” (or “computer readable medium”) refers to any computer program product, apparatus and/or device, such as for example magnetic discs, optical disks, memory, and Programmable Logic Devices (PLDs), used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” (or “computer readable signal”) refers to any signal used to provide machine instructions and/or data to a programmable processor. The machine-readable medium can store such machine instructions non-transitorily, such as for example as would a non-transient solid-state memory or a magnetic hard drive or any equivalent storage medium. The machine-readable medium can alternatively or additionally store such machine instructions in a transient manner, such as for example as would a processor cache or other random access memory associated with one or more physical processor cores. 
     To provide for interaction with a user, one or more aspects or features of the subject matter described herein can be implemented on a computer having a display device, such as for example a cathode ray tube (CRT) or a liquid crystal display (LCD) or a light emitting diode (LED) monitor for displaying information to the user and a keyboard and a pointing device, such as for example a mouse or a trackball, by which the user may provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, such as for example visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including, but not limited to, acoustic, speech, or tactile input. Other possible input devices include, but are not limited to, touch screens or other touch-sensitive devices such as single or multi-point resistive or capacitive trackpads, voice recognition hardware and software, optical scanners, optical pointers, digital image capture devices and associated interpretation software, and the like. 
     In the descriptions above and in the claims, phrases such as “at least one of” or “one or more of” may occur followed by a conjunctive list of elements or features. The term “and/or” may also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases “at least one of A and B;” “one or more of A and B;” and “A and/or B” are each intended to mean “A alone, B alone, or A and B together.” A similar interpretation is also intended for lists including three or more items. For example, the phrases “at least one of A, B, and C;” “one or more of A, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together.” Use of the term “based on,” above and in the claims is intended to mean, “based at least in part on,” such that an unrecited feature or element is also permissible. 
     The subject matter described herein can be embodied in systems, apparatus, methods, computer programs and/or articles depending on the desired configuration. Any methods or the logic flows depicted in the accompanying figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. The implementations described above can be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of further features noted above. Furthermore, above described advantages are not intended to limit the application of any issued claims to processes and structures accomplishing any or all of the advantages. 
     Additionally, section headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Further, the description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Neither is the “Summary” to be considered as a characterization of the invention(s) set forth in issued claims. Furthermore, any reference to this disclosure in general or use of the word “invention” in the singular is not intended to imply any limitation on the scope of the claims set forth below. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby.