Torque conductor for improved torque transmission in a wire system for cardiac

Abstract

The present invention relates to a screwing lead core for improving torque transmission from a physician's hand to a lead end (e.g., a spiral) of a lead device. A lead end is provided for ease of manipulation, and a screwdriver function of screwing a lead core is provided to improve torque transmission to the lead end of the lead device to better control the piercing process. The screwed lead core may directly engage the end of the wire arrangement, allowing torque to be efficiently transmitted directly to a fixed helix at the end.

Description

Technical Field

[0001] The present invention relates to the field of lead devices (such as electrode catheters) for cardiac pacing systems, such as (but not limited to) left bundle branch pacing (LBBP), cardiac resynchronization, or tachycardia systems. Background Art

[0002] The following terms and their abbreviations may be used in the present disclosure: electrocardiogram (ECG), left ventricle (LV), right ventricle (RV), left atrium (LA), right atrium (RA), right ventricular apex (RVA), His bundle pacing (HBP), left anterior oblique (LAO), right anterior oblique (RAO), left bundle branch (LBB), right bundle branch (RBB), left bundle branch pacing (LBBP), left bundle branch block (LBBB), left ventricular activation time (LVAT), right bundle branch block (RBBB), ventricular septum (VS), sinoatrial node (SAN), atrioventricular node (AVN), interventricular septum (IVS), right ventricular outflow tract (RVOT) pacing, direct His bundle pacing (DHBP), and para-Hisian pacing (PHP).

[0003] Different electrical activation sequences of cardiac pacing may result in different mechanical pump efficiencies of the stimulated heart. Rapid and uniform cardiac ventricular contractions are required to optimize pump efficiency.

[0004] Traditional pacing sites (such as RVA) can provide a stable lead position with a low displacement rate, but are not effective in optimizing LV contraction (which accounts for about 80% of the heart mass). Long-term right ventricular apex pacing may have a harmful effect on left ventricular function by inducing iatrogenic left bundle branch block, which has a great impact on left ventricular hemodynamic performance. This observation has prompted a re-evaluation of traditional methods and the study of alternative pacing sites in order to obtain a more physiological ventricular activation pattern and avoid harmful effects. Attempts have been made at RVOT pacing, DHBP, PHP, and dual-site (RVA + RVOT) pacing.

[0005] LBBP has emerged as an alternative method for delivering physiological pacing to achieve electrical synchronization of the LV, especially for patients with infra-nodal atrioventricular block and / or LBBB. The proximal LBB traverses the LV septum and spreads out, forming a wider pacing target compared to the His bundle. An LBBP technique using a ventricular transseptal approach (i.e., pacing the LV from the RV) has been developed. It has been reported that LBBP provides a low pacing threshold and a large R wave, and due to the target being the distal conduction system, the theoretical risk of distal conduction block is low.

[0006] However, challenges remain regarding: minimizing the impact of the pacing device passing through the septum (such as permanent arterial damage), reducing the puncture size at the septum and controlling the puncture process at the septum, and ensuring the long-term reliability of the pacing device exposed to septal contraction limiting factors. Summary of the Invention

[0007] The object of the present invention is to provide an electrode catheter system to address the above challenges associated with LBBP or other pacing methods.

[0008] This object is achieved by a screwing stylet according to claim 1, a wire system according to claim 9, and a method according to claim 10.

[0009] According to a first aspect, a screwing stylet is configured to be insertable into a lead body of a lead device and includes a coupling end configured to be able to engage a driver at the lead end of the lead device to transmit torque to the lead end.

[0010] According to a second aspect, a wire system includes the screwing stylet of the first aspect and a lead device, the lead device including a lead end having a driver configured to be able to engage the coupling end of the screwing stylet when the screwing stylet is inserted into the lead device.

[0011] According to a third aspect, a method of transmitting torque to a lead end of a lead device placed in a target area of a human or animal body is provided, the method comprising:

[0012] Inserting the screwing stylet into the lead device until the coupling end of the screwing stylet engages the driver of the lead end;

[0013] Pushing an operating handle fixed to a connector end of the screwing stylet opposite the coupling end, and due to elastic elongation of the lead body of the lead device, a connection force is generated between the coupling end of the screwing stylet and the driver;

[0014] Using a locking element of the operating handle to lock the operating handle to the lead body to maintain the connection force;

[0015] Rotating the screwing stylet to transmit torque to the lead end via the driver.

[0016] Thus, by assembling the twisting guide core and the wire device, the manipulation of the wire system and the torque transmission to the end of the wire device can be improved, thereby better controlling the puncture process. The twisting guide core can directly engage the end of the wire device, allowing the torque to be directly and effectively transmitted to the fixed helix at the end and improving the manipulation performed by the physician.

[0017] According to the first option of any one of the first to third aspects, the twisting guide core may further include a conical portion and / or a reduced-diameter portion at the coupling end to increase flexibility. Thus, in the bending portion, the insertion of the twisting guide core into the inserted wire device can be facilitated.

[0018] According to the second option of any one of the first to third aspects, the twisting guide core may be made of stainless steel or nitinol. Thus, a rigid or highly flexible twisting guide core can be provided.

[0019] According to the third option of any one of the first to third aspects, which can be combined with the first or second option, the twisting guide core may further include an operating handle fixed to the opposite end of the coupling end. Thus, the inserted twisting guide core can be easily rotated via the operating handle.

[0020] According to the fourth option of any one of the first to third aspects, which can be combined with any one of the first to third options, the operating handle of the twisting guide core may further include an annular opening surrounding the twisting guide core and configured to receive an end portion of the connector of the wire device. Thus, the stylet with the integrated operating handle can be easily fixed to the wire device simply by continuing the insertion process until the end portion of the connector of the wire device has been inserted into the operating handle.

[0021] According to the fifth option of any one of the first to third aspects, which can be combined with any one of the first to fourth options, the operating handle of the twisting guide core may further include a locking element for fixing the end portion of the connector of the wire device within the annular opening to the twisting guide core. Thereby, a quick and easy locking mechanism can be provided, where the locking element is activated when the end portion of the connector of the wire device has been inserted into the operating handle and the elastic elongation of the wire body has reached sufficient connection force. The locking element may include a screw, a bolt, and a hole, or a driver handle and a threaded portion on the end portion to provide the locking mechanism.

[0022] According to the sixth option of any one of the first to third aspects, which can be combined with any one of the first to fifth options, the locking element of the operating handle of the twisting guide core may be configured to be connectable to a signal analyzer via a cable to transmit a signal from the coupling end to the signal analyzer. Thus, the physician can easily connect the wire device of the inserted twisting guide core to the signal analyzer to support the placement process.

[0023] According to a seventh option of any one of the first to third aspects, which can be combined with any one of the first to sixth options, the screwing guide core may further include an end portion extending from the operating handle, and the signal analyzer can be rotatably connected to the end portion via a cable to transmit signals from the connection end to the signal analyzer. Therefore, a cost-saving "linear" connection can be achieved, and there is an option of rotating / sliding electrical connection (e.g., via alligator clips) around the guide core body.

[0024] It should be understood that the screwing guide core according to claim 1, the wire system according to claim 9, and the method according to claim 10 may have similar and / or identical preferred embodiments, especially those defined by the dependent claims.

[0025] It should be further understood that the preferred embodiments of the present invention may also be any combination of the dependent claims or the above embodiments and the corresponding independent claims.

[0026] These and other aspects of the present invention will be apparent and elucidated with reference to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In the following drawings:

[0028] Figure 1 A flowchart of a procedure for placing an LBBP lead device according to various embodiments is schematically shown;

[0029] Figure 2 A heart with a lead device placed for RVA pacing is schematically shown;

[0030] Figure 3 A heart with the LBB pacing site indicated is schematically shown;

[0031] Figure 4 A heart with a lead device placed for transseptal ventricular LBB pacing is schematically shown;

[0032] Figure 5 A lead device according to an embodiment is schematically shown;

[0033] Figure 6 A lead device according to an embodiment is schematically shown, where the dimensional parameters are marked;

[0034] Figure 7 The disassembled part and the assembled part of a lead device according to an embodiment are schematically shown;

[0035] Figure 8Schematically shows a disassembled portion and an assembled portion of a wire device according to an embodiment with modified signal taps;

[0036] Figure 9 Schematically shows a side view and a cross-sectional view of a driver handle of a screwdriver-type guide core of a wire device according to an embodiment;

[0037] Figure 10 Shows a graph of wire torque versus the number of turns of wire rotation achieved by a wire device according to an embodiment compared to a conventional wire device; and

[0038] Figure 11 Schematically shows a wire device having a molded spiral structure according to an embodiment. DETAILED DESCRIPTION

[0039] Various embodiments of the present invention will now be described based on an improved wire system structure having a wire device (e.g., an electrode catheter) and an insertable screwdriver guide core. Although the present invention is particularly advantageous in the context of transseptal pacing (such as LBBP), the present invention is not limited thereto and can also be used in combination with other pacing types and / or other sites of applications where wire devices need to be placed.

[0040] It should be noted that throughout this disclosure, only those modules, components, and / or devices related to the proposed wire system structure and placement operation are shown in the drawings. For the sake of brevity, other modules are omitted. In addition, components designated by the same reference numerals or numbers are intended to have the same or at least similar functions, and thus their functions will not be described later.

[0041] LBBP is defined as capture of the LBB (i.e., the left bundle trunk or its proximal branches), typically capture of the septal myocardium at low output (e.g., <1.0V / 0.4ms).

[0042] Figure 1 Shows an exemplary flowchart of a procedure for placing or implanting an LBBP wire device.

[0043] In the first step S101 (“VST?”), the thickness of the interventricular septum is evaluated by echo and / or scar measurement. The IVS separates the LV and RV and plays an important role in the function of both ventricles. In one example, echocardiogram measurements can be used to measure the septal thickness, e.g., measuring the septal thickness from the clearest echo (including the left and right endocardial surfaces at end-diastole), which can be determined by the R-wave peak of the simultaneously recorded ECG.

[0044] Based on the intrinsic cardiac rhythm derived from the ECG measurement, the presence or absence of LBBB is determined in step S102a ("LBBB") or S102b ("N-LBBB") respectively. LBBB completely changes the electrical activation of the LV and the QRS complex on the ECG. Under physiological conditions, the septum, which is normally on the left side, has its activation originating from its right side. Then the electrical impulse propagates downward, to the left, and slightly forward. This results in non-uniform and delayed depolarization of the LV.

[0045] The ECG criteria for LBBB may include at least one of the following: QRS duration greater than 120 ms, absence of Q wave in leads I, V5, and V6, monomorphic R wave in leads I, V5, and V6, and ST and T wave displacements opposite to the main deflection of the QRS complex.

[0046] A simple way to diagnose LBBB in an ECG with a widened QRS complex (>120 ms) can be to look at lead V1. If the QRS complex is widened and deflected downward in lead V1, then LBBB is present. If the QRS complex is widened and deflected upward in lead V1, then RBBB is present.

[0047] If LBBB has been determined in step S102a, then additional ventricular backup pacing ("V-BUP") is added in step S103.

[0048] Regardless of the presence or absence of LBBB, venous access is performed from the left side via a lead device in step S104 ("VACC(LS)").

[0049] Then, in step S105 ("VS(LAO30°)LBBP"), the initial site of the LBBP position on the right surface of the ventricular septum (e.g., RAO 30°) is determined. This can be achieved by placing the catheter about 1 to 1.5 cm away from the HBP site towards the RVA and / or by using a pacing morphology, where a notch "W" pattern in lead V1 closer to the lowest point (the deepest point of the QRS signal) may indicate the ideal position. Then the pacing lead (e.g., a helical electrode) is vertically screwed into the LV septum (LAO 30 - 45°).

[0050] If an error ("ERR") due to fixation failure is determined in step S105, then re-evaluation ("RASS") is initiated in step S106.

[0051] Then, in step S107 ("DET LD"), the depth of the LBBP lead entering the ventricular septum is determined. This can be achieved by observing at least one of the following: changes in the notch in lead V1, sheath angiography, pivot sign, and impedance monitoring.

[0052] The pacing lead is slowly rotated to a depth of approximately 6 to 8 mm and / or based on a RBBB pacing morphology, while avoiding any septal perforation.

[0053] Finally, in step S108 (“CONF LBBP CPT”), LBB capture is confirmed based on acceptable pacing parameters. The confirmation can be based on at least one of the following: the pacing morphology in RBBB mode, the recording of the LBB potential, the stimulus peak of LVAT (suddenly shortening as the output increases or remaining shortest and constant at low and high outputs), selective LBBP and non-selective LBBP, and the recording of retrograde His potential or antegrade LBB potential during pacing.

[0054] In summary, the common features of the implantation or placement process include transvenous access, placement of the pacing lead through the ventricular septum to the subendocardium of the LV septum in the LBB region, and confirmation of capture of the LBB.

[0055] In the case of RBBB, when the pacing lead is placed from the RV septum through the ventricular septum to the subendocardium of the LV septum in the LBB region, the pacing QRS morphology of the electrocardiogram (ECG) changes from LBBB to right bundle branch block (RBBB) mode because the LV is activated earlier than the RV. However, the pacing morphology may be affected by the pacing site of the LBB, existing bundle branch disease, or selective or non-selective capture of the LBB.

[0056] Figure 2 The heart with a lead device placed for RVA pacing is schematically shown.

[0057] In normal cardiac function, the heartbeat begins in the heart itself due to the SAN, which is located at the top of the RA and sets the rate of cardiac contraction. It emits electrical impulses that are transmitted through the muscular walls of the two atria. These impulses cause atrial systole. Then, the impulses are transmitted to another node inside the heart - the AVN. This node is in the lower part of the RA. Once the impulses from the SAN reach the AVN, the impulses are transmitted to the conduction fibers, which travel down along the central wall of the heart. Then, the impulses split and travel upward to the LV and RV, causing them to contract simultaneously (ventricular systole).

[0058] Important elements of the cardiac conduction system are located inside the septum (IVS) 24. The His bundle travels subendocardially, about 1 cm down the right side of the septum 24, and then divides into the LBB and RBB. The LBB continues down the right side of the septum 24, while the LBB crosses to reach the left side and branches into the anterior fascicle and posterior fascicle.

[0059] Under normal circumstances, the excitation of the SAN controls the heart rhythm. Sinus rhythm abnormalities can lead to arrhythmias, which refer to abnormalities in the rate, rhythm, origin site, and conduction of cardiac electrical impulses. When specific intraventricular conduction fibers are diseased, the repolarization wave must travel through slower intermuscular conduction to reach the ventricles. Classic disorders associated with conditions involving different conduction fascicles include LBBB and RBBB. An ECG can be used to measure and record cardiac electrical activity and thus provide important information about cardiac function. The ECG has been used as a standard diagnostic tool for analyzing arrhythmias.

[0060] RVA pacing 26 via the lead device 200 (including the pacing lead 20) results in an abnormal contraction pattern, followed by asynchrony of the LV free wall and septum 24, which can lead to myocardial perfusion defects, histopathological changes, left ventricular dilation, and both systolic and diastolic left ventricular dysfunction. All of these long-term changes can explain the higher morbidity and mortality observed in patients undergoing chronic RVA pacing 26 compared to atrial pacing.

[0061] Two different cardiac electrical activation speeds can be observed. These are the first activation speed (slow conduction / contraction) via myocytes (i.e., muscle cells) ( Figure 2 as indicated by the small and medium arrows) and the second activation speed (fast conduction) through the Purkinje fibers 22 (i.e., the subendocardial branches), where the second speed is approximately ten times the first speed. Thus, the Purkinje fibers 22 can be regarded as a kind of stimulation "highway".

[0062] Figure 3 A heart with the LBB pacing site 28 indicated is schematically shown.

[0063] The LBB pacing site 28 is located at the Purkinje fibers 22 of the LV and thus activates a more physiological contraction by providing synchrony of the LV free wall and septum 24.

[0064] Figure 4 A heart with the lead device 200 inserted is schematically shown, where the pacing lead 20 is placed for transseptal ventricular LBBP. The placement of the pacing lead 20 can be carried out based on the procedure explained above in conjunction with Figure 1 the explanations.

[0065] Therefore, pacing the LV from the RV via a transseptal ventricular approach serves as a guide for catheter delivery.

[0066] The following embodiments of the proposed lead system are configured to minimize the impact of lead device insertion through septum 24 by reducing the puncture area (e.g., to prevent permanent damage to the artery), provide enhanced control of the puncture process through an improved torque transfer mechanism with an insertable and twistable guide core, and ensure long-term reliability of the lead device exposed to the contractile limitations of septum 24 by providing a small and robust structure and / or continuous flexibility.

[0067] The body of the lead device can be configured to improve the smoothness of contact with a guiding catheter used to direct the lead device (e.g., through a blood vessel) to a target area. This can be achieved by using, for example, a polyurethane (PU) material with a reduced diameter to allow the lead body to advance easily through the guiding catheter and the lead tip to advance easily through septum 24.

[0068] A suitable design for the lead device can have a multi-lumen, coaxial, and coradial structure, which can be used as either a tachycardia lead or a bradycardia lead, provided that a central lumen for the passage of the guide core is provided. The coaxial lead has an inner conductor that extends down the length of the lead to the tip electrode (cathode), and the inner conductor is arranged in a coil configuration with a central lumen to allow the guide core to pass through during implantation. The coil can be covered by a cylindrical length of inner insulation, which in turn can be wrapped by another coil conductor that also extends down the lead to the annular electrode (anode). A second outer insulation layer and a lead cover protect the annular conductor from the external environment, thus completing the design. The coradial bipolar lead addresses some of the volume and stiffness issues of coaxial leads in a four-layer design by providing a new conductor and insulator technology, where a single coil extends down the length of the lead (also with a central lumen to allow insertion of the guide core) and consists of two or four parallel, alternating insulated conductor strands, with one or two connected to the cathode and the other one or two connected to the anode. Each conductor strand can be individually coated with an adhesive layer, such as ethylene tetrafluoroethylene (ETFE) fluoropolymer insulation, which insulates each strand from the other, even though they are intertwined. The single two-component coil can be surrounded by a single outer insulation cover.

[0069] The multi-lumen or coaxial or coradial lead can optionally include a fixed, non-retractable helix to minimize size. However, a retractable helix can also be used in conjunction with the described embodiments.

[0070] In addition, the proposed lead system can be configured to provide improved torque capabilities, i.e., the ability to safely transfer torque to the helix (e.g., full lead body torque) and compatibility with a lead core drive to simplify manipulation (e.g., by push transmission). In one example, a coaxial lead with a compatible screwing lead core (screwdriver lead core) can be provided, as described later.

[0071] For the design of the distal end (distality) of the lead device, the ratio of the outer diameter of the helix to the outer diameter of the housing should be greater than 70%, ideally 100%, where an equal-profile distality design can be provided to avoid a front blocking surface.

[0072] In addition, a rigid helix can be provided to avoid deformation of the helix during screwing, while a fixed helix (i.e., a lock between the helix and the lead body) can simplify manipulation (i.e., the ability to retract the system without the need for a parasitic tool).

[0073] Furthermore, design flexibility can be provided by adjusting the interelectrode distance for bilateral pacing to accommodate different thicknesses of the septum 24.

[0074] The distal design of the lead device can be further configured to allow the distal end of the lead to smoothly and predictably advance into the septum 24 until the helix (cathode) reaches the desired position in the LV chamber, i.e., close to the LBB, without completely perforating the septum 24 such that the helix does not protrude into the LV chamber.

[0075] In addition, the design of the lead device can be configured to minimize the energy required to puncture the septum 24. This can be achieved by providing a dedicated distal conical tip having a conical shape, e.g., for the interelectrode section (between the distal helix end and the proximal anode end).

[0076] Next, reference will be made to Figures 5 to 9 and 11 to describe various embodiments of the proposed lead system with a lead device and a separate insertable screwing lead core 55.

[0077] Figure 5 A partially disassembled lead system (the screwing lead core 55 has not been fully inserted) according to an embodiment is schematically shown, which is partially introduced into the septum 24 according to the desired depth required for, e.g., LBBP.

[0078] The proposed wire system includes a helix 51 that is mounted (e.g., welded) on a driver 52, which may include a surrounding coil 58 or other non-flat regular or irregular surface structures to ensure good adhesion of the surrounding material of the wire body 54 to the driver 52 in the inter-electrode portion, thereby obtaining a simple, rigid, and durable wire end structure with a small number of components, thus improving long-term reliability. The driver 52 is fixedly supported in the wire body 54 and is mechanically and electrically connected to a screwing core adapter 53, which mates with a coupling end (engagement portion) 56 for inserting a separate screwing core 55, and the coupling end has a screwdriver function to allow the helix 51 to be rotationally driven via the driver 52. Due to the electrical connection between the helix 51 and the screwing core 55, the electrical signal sensed by the helix 51 in the target area can be routed to a signal analyzer via the screwing core 55 and used to monitor the correct placement of the helix 51 during the screwing operation without disconnecting the alligator clips, allowing a single-step operation (eliminating the need for the sequence of screwing, connecting clips, electrical measurement, disconnecting clips, additional screwing, connecting clips, etc.).

[0079] Typical dimensions of the screwing core 55 can be a nominal diameter in the range of 0.30 mm to 0.50 mm, a reduced diameter of the distal portion between 0.10 mm and 0.25 mm to enhance flexibility, and a length of the reduced diameter between 0 mm and 200 mm. The screwing core can be made of stainless steel (e.g., classic inox 304 or 306 in the standard version) or a highly elastic material such as nitinol, which is more efficient and robust, can withstand torque limits, and avoid any risk of breakage during use.

[0080] In Figure 5 it, the screwing core 55 has not been fully inserted into and engaged with the adapter 53 of the driver 52.

[0081] The adapter 53 can be an integral part of the driver 52 or can be removably or non-removably fixed to the driver 52 to allow adaptation to different types of screwing cores 55 with different shapes or sizes of their coupling ends 56.

[0082] In this embodiment, the coupling end 56 of the screwing core includes a flat shape (similar to a screwdriver). The adapter 53 includes mating components (e.g., matching slots or recesses) for accommodating the coupling end 56 of the screwing core 55.

[0083] More generally, the coupling end 56 of the screwing guide core 55 can include one of a plurality of cavities or protrusions to allow torque to be applied to the mating part of the driver 52. Examples are the slotted drive type, the cross drive type, the square drive type, the multi-square drive type, the hexagon drive type, the Phillips drive type, the internal Phillips (Torx) drive type, the combination (cross-slotted) drive type, the external drive type or the anti-tamper drive type.

[0084] The proposed configuration of the wire system with the driver 52, the optional adapter 53 and the screwing guide core 55 optimizes the torque transmission from the physician's hand to the helix 51 and minimizes the friction of the wire body 54 in the guiding catheter during placement.

[0085] In addition, the wire body 54 includes an anode 57 and an optional conical interelectrode section between the helix 51 (cathode) and the anode 57. Electrical signals (e.g., pacing signals) to the helix 51 and the anode 57 are transmitted along the wire device in the respective coated lines 59. In Figure 5 the example shown, each electrode (i.e., the welded anode 57 and the cathode at the helix 51) uses two insulated wires.

[0086] Figure 5 The coaxial structure of the wire device allows a wire body 54 with reduced dimensions (e.g., 4.8F) to be combined with a PU insulator. In addition, a simple and robust structure with a minimum number of components can be provided to minimize the stiffness gradient and the number of welded, and / or glued parts or other weak connection points.

[0087] The insulating plastic material around the rigid driver 28 can be reflowed onto the driver 52 so that no residual gap remains between the two elements, which are exposed to a high level of gap compression. Thus, local bending stresses and the resulting risk of long-term plastic cracks can be prevented.

[0088] Figure 6 is schematically shown Figure 5 of the wire system, in which the screwing guide core 55 is fully inserted, and the following dimensional parameters are marked: the outer diameter Dl of the distal section of the wire housing at the helix 51, the outer diameter Dh of the helix 51, the outer diameter Da of the proximal welded anode 57, the length Lh of the helix 51, and the total length Lt of the wire end, which includes the distal helix 51 and the conical or tapered part of the wire body 54, which surrounds the driver 52 between the helix 51 and the proximal anode 57.

[0089] The ratio Dh / Dl can be set between 0.8 and 1, while Dh can be set between 1 and 1.8 mm (preferably 1.40 mm). Da can be set between 1.25 mm and 1.94 mm (preferably 1.66 mm), Lt can be set between 8 and 15 mm, and Lh can be set between 1.5 and 5 mm.

[0090] The proposed specific conical shape with the above-mentioned dimensional ranges ensures that the wire end with the helix 51 can puncture the tissue in the target area in a controlled and smooth manner, providing a conical profile and minimizing the energy required for the puncture.

[0091] Figure 7 Schematically shown is a disassembled and assembled wire system according to an embodiment with a screwing guide core 55 having an integrated operating handle (screwdriver handle) 83.

[0092] In Figure 7 the upper part shows the separate screwing guide core 55, which has an integrated operating handle 83 and a locking element (e.g., a metal lateral locking screw) 85 for fixing the screwing guide core 55 to the hollow end portion 81 of the connector (e.g., IS1 connector) 82 of the wire device. The screwing guide core 55 may include a conical portion with a reduced diameter at its distal end, followed by a flexible portion with a constant diameter and a flat coupling end 56 for coupling to the driver 52 of the wire device.

[0093] In Figure 7 the middle part shows the wire device with the helix 51, the driver 52 with an integrated mating portion for the coupling end 56 of the screwing guide core 55 to be inserted, the connector 82 and its end portion 81.

[0094] Finally, in Figure 7 the lower part shows the assembled wire system with the wire device and the inserted and coupled screwing guide core 55, where the helix 51 is correctly positioned for LBBP to receive the ORS signal from the LBB. The screwing guide core 55 has been inserted through the hollow end portion 81 of the connector 82 of the catheter and coupled to the driver 52, while the end portion 81 of the connector 82 has been inserted into the annular opening around the integrated operating handle 83 of the screwing guide core 55 and fixed by the locking element 85.

[0095] In Figure 7 the embodiment, the signal analyzer 86 can be connected via a cable (e.g., a pacing system analyzer (PSA) cable) 84 to the locking element 85, which is coupled to the screwing guide core 55 via the end portion 81 of the connector 82 of the catheter.

[0096] Thus, the QRS signal from the LBB can be routed through the helix 51, the driver 52, the screwing mandrel 55, the locking element 85, and the PSA cable 84 to the signal analyzer 86, which can be used to monitor the correct placement of the lead device during the puncture.

[0097] It is noted that Figure 7 only the schematic functional components are shown, and for the sake of simplicity, the wiring of the pacing signal, the lead tip, and its shape and anode have been omitted.

[0098] As Figure 7 shown, the lead body of the lead device can be configured to allow elastic elongation L+Δl (e.g., Δl = 1 to 10 mm) in response to a force applied to the lead body. The resulting axial elasticity of the connection system generates a compressive force F, ensuring that during the placement procedure, despite many limitations associated with the puncture process (traction, pushing, torque, bending, etc.), the coupling end 56 of the screwing mandrel 55 still engages stably and reliably into the driver 52. It also ensures a temporary electrical connection between the driver 52 and the screwing mandrel 55 to reduce artifacts or other interference in the electrical signal transmitted to the signal analyzer 86.

[0099] The integrated operating handle 83 provides a simple "hands-free" locking handle for operating the lead device to achieve improved torque transfer from the physician's hand to the helix 51 via the screwing mandrel 55 and the driver 52.

[0100] The non-retractable fixed helix 51 facilitates the manipulation of the lead device because no special tool is required for the retraction mechanism, and there is no risk of improper manipulation.

[0101] The screwing mandrel 55 (which can be provided as a separate adapter attachment for the lead device) provides a screwdriver function for transmitting increased torque during a challenging puncture process. The screwing mandrel 55 directly engages the driver 52 at the end of the lead, thereby allowing torque to be directly and effectively transmitted to the fixed helix 51. This proposed arrangement also minimizes any stress applied to the internal structure of the lead device during the puncture (e.g., through glued and / or welded parts, etc.).

[0102] The material and design of the twist core 55 can be selected to achieve high flexibility at the last 10 cm before the coupling end 56 (e.g., via a conical and / or reduced diameter section) to easily pass through the two curves of the guiding catheter within the heart and avoid any risk of the tip detaching from the target area during insertion of the twist core 55. Additionally, despite the reduced distal diameter, high torque transmission (higher than the wire body) can be achieved, and a "hands-free" simple locking and operating handle 83 is provided to engage the distal coupling end (e.g., flat end) 56 of the twist core 55 into a mating part (e.g., jack) at the driver 52 (or adapter 53) for the twisting operation.

[0103] Figure 8 The disassembly and assembly parts of a wire device according to an embodiment are schematically shown, where the modified signal tap is provided by the twist core 55 having locking, torque, and mapping functions.

[0104] As with Figure 7 Similarly, Figure 8 only the schematic functional components are shown, and for the sake of brevity, the wiring of the pacing signal and the wire tip and its shape and anode have been omitted.

[0105] Here, the operating handle 83 is modified such that the end portion of the twist core 55 protrudes from the operating handle 83 and can be used to connect a signal analyzer 86 via an alligator clip of, for example, a cable 84 (e.g., PSA cable).

[0106] Thus, the body of the twist core 55 passes directly through the operating handle 83 to achieve a cost-saving "straight-line" connection, and an electrically connectable rotation / sliding around the core body can be selected, e.g., via an alligator clip on the cable 84.

[0107] Figure 9 A perspective view (left part) and a cross-sectional view (right part) of the operating handle 83 of the twist core 55 of a wire device according to an embodiment are schematically shown.

[0108] The wire or body of the twist core 55 and its flat coupling end 56 are fixed to the operating handle 83 (by molding, etc.) and locked in a translational and rotational manner. A lateral locking element 85 can be used to temporarily connect / lock the operating handle 83 to the end portion (not shown) of a connector (e.g., IS1 connector pin) of the wire device. The protruding end portion of the twist core 55 includes a connection end 87 for connecting a cable to a signal analyzer, etc.

[0109] Thus, a physician can place the lead device into a target area. For example, first, the lead device without the screwing mandrel 55 is inserted through a blood vessel via, for example, a guiding catheter until the helix 51 reaches the target area. Then, the physician can insert the screwing mandrel 55 until the screwing mandrel engages with the driver 52, and can push the operating handle 83 fixed on the screwing mandrel 55. The operating handle is at the connector end opposite to the coupling end 56, and a connecting force is generated between the coupling end 56 of the screwing mandrel 55 and the driver 52 due to the elastic elongation of the lead body 54 of the lead device. Then, the physician can lock the position of the operating handle 83 to the lead body 54 by using the locking element 85 of the operating handle 83 to maintain the connecting force, and then can rotate the operating handle 83 (or the connector 82) to screw the helix 51 into the target area (e.g., the septum). He / She can further capture the electrical induction (e.g., QRS signal) at the level of the helix by using the temporary electrical connection through the screwing mandrel 55 and identify when the helix 51 engages with the LBB or another target position. This allows for easy one-handed ("hands-free") placement of the helix 51 via the handle 83 (or the connector 82).

[0110] Thus, the proposed two-component lead system can be configured to temporarily fix or lock the two ends of the assembled lead device and the screwing mandrel 55, wherein the distal flat end (coupling end 56) of the screwing mandrel 55 engages with the mating part of the driver 52 under a predetermined force determined by the elastic elongation of the lead body 54. Therefore, during the critical screwing operation of placing the lead device, an important temporary increase in torque transmission can be achieved, along with an improvement in operating comfort. Both the lead device and the screwing mandrel 55 can be temporarily operated as a single device to free one hand of the doctor.

[0111] Figure 10 A graph showing the lead torque versus the number of turns of lead rotation achieved by the lead system according to an embodiment compared to a conventional lead device is shown.

[0112] This figure shows an improved torque curve 90 achieved by the proposed lead system with a screwing mandrel and a driver handle compared to a set of torque curves 92 achieved only by a conventional lead device and a screwing mandrel.

[0113] More particularly, the improved torque curve 90 corresponds to the sum of the uppermost curve of group 92 (which corresponds only to the screwing guide core) and the curve of only the wire device (one of the lower curves of group 92). Although the screwing guide core alone provides better torque transmission (an increase of about 10% to 20%), the sum of the screwing guide core and the wire body increases the torque by 100% compared to the wire device alone. Thus, temporarily connecting the two components (the screwing guide core and the wire device) of the proposed wire system during placement of the wire device essentially improves torque transmission and ease of use for the physician. To achieve the same performance without temporarily connecting the two components, the physician would have to rotate the two devices simultaneously at the same speed, which is nearly impossible considering all the other things he / she has to handle during this critical step (e.g., analyzer signals, patient parameters, etc.).

[0114] It can be inferred from the Figure 10 chart that the improved torque curve 90 shows that as the number of turns of rotation increases, the wire torque increases rather steadily, which facilitates the smooth and predictable advancement of the helix of the wire device into the septum or other target area.

[0115] Figure 11 A wire device having a helical structure 120 is shown, the helical structure having been molded or otherwise formed on or attached to the outer surface of the interelectrode portion of the wire body 54 between the helix 51 and the welded anode 57. The pitch of the windings of the helical structure can substantially correspond to the pitch of the helix 51 to allow for smooth insertion of the interelectrode portion after LBBP is performed during penetration of the tissue by the helix 51 at the target area (e.g., the septum).

[0116] Additionally, the wire device having the helical structure 120 can be used with or without the screwing guide core as explained above in connection with other embodiments. In the first case, Figure 11 the wire device includes a driver that can be coupled to the screwing guide core.

[0117] It is noted that Figure 11 the dimensions of the end of the Figure 7 and 8 the other wire devices of Figure 6 can also correspond to the dimensions shown in

[0118] In summary, a screwing guide core is described for improved torque transmission from the physician's hand to the wire end (e.g., the helix) of the wire device. The wire end is provided for ease of manipulation, and the screwdriver function of the screwing guide core is provided to improve torque transmission to the wire end of the wire device for better control of the puncture process. The screwing guide core can directly engage the end of the wire device, thereby allowing for direct and effective torque transmission to the fixed helix at the end.

[0119] Although the present invention has been shown and described in detail in the drawings and the foregoing description, such showings and descriptions should be considered illustrative or exemplary and not restrictive. The present invention is not limited to the above embodiments. The present invention can be applied to various types of lead devices (e.g., bradycardia or tachycardia lead devices having a multi-lumen, coaxial or concentric structure) and applications in the field of cardiac pacing or sensing systems. In addition, the screwing core can be provided as an integral part of the lead device and is not detachable from the lead body.

[0120] The proposed screwing core system (more precisely its handle) can be configured to fit or be capable of fitting an IS1, IS4 (low voltage) or DF4 (high voltage) connector. For example, the handle can be configured to provide a temporary connection to all connector rings for mapping purposes.

[0121] In one example, the LBB screwdriver handle 83 can be connected to and cover the IS1 connector, while the lateral locking element (e.g., a metal screw) 85 can engage the IS1 pin to ensure a mechanical connection to the lead body structure.

[0122] More particularly, the handle 83 can be capable of being connected to the helix 51 (either through the core 55 or through the locking element 85 engaging the IS1 pin) and the IS1 ring electrode (connected to the anode). This makes the handle 83 more complex but provides a better signal to discern LBB capture. The connection element can be a radial spring connected to the IS1 ring electrode and axially extending for a wired connection, e.g., via an alligator clip. This concept can be extended to the IS4 and DF4 connectors to connect all four connector poles.

[0123] In another example, compatibility with a retractable helix system can be provided, e.g., a brady lead system with a retractable helix for LBB therapy. The proposed screwdriver core system also provides an advantageous solution for such leads. In this case, the locking element (e.g., a metal screw) 85 can engage the IS1 pin and / or the IS1 ring. If it is to engage both types of electrodes, two lateral locking elements (e.g., screws) can be provided, the locking element 85 plus another locking element configured to engage the IS1 ring. If it is to engage the IS1 ring, the locking element 85 can be configured to face the IS1 ring.

[0124] The IS1 pin can be capable of rotating and capable of being connected to an inner coil structure to activate the helix extension of a retractable helix system.

[0125] By studying the drawings, the disclosure, and the appended claims, those skilled in the art can understand and realize other variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. The foregoing description details certain embodiments of the invention. However, it should be understood that, however detailed the foregoing may appear in the text, the invention may be practiced in many ways and is therefore not limited to the disclosed embodiments. It should be noted that the use of a particular term when describing certain features or aspects of the invention should not be construed as implying that the term is redefined herein to limit any specific property of the invention that includes the features or aspects associated with the term.

Claims

1. A screwing guide core (55) configured to be insertable into a wire body (54) of a wire device and including a coupling end (56) configured to be able to engage a driver (52) at the wire end of the wire device so as to transmit torque to the wire end.

2. The screwing guide core (55) according to claim 1, further including a conical portion and / or a reduced diameter portion at the coupling end (56) to increase the flexibility of its distal section.

3. The screwing guide core according to claim 1 or 2, wherein, the screwing guide core is made of stainless steel or nitinol.

4. The screwing guide core (55) according to any one of claims 1 to 3, further including an operating handle (83) fixed to an opposite end of the coupling end (56).

5. The screwing guide core (55) according to claim 4, wherein, the operating handle (83) includes an annular opening around the screwing guide core (55) and is configured to receive an end portion (81) of a connector (82) of the wire device at an opposite end of the wire end.

6. The screwing guide core (55) according to claim 5, wherein, the operating handle (83) includes a locking element (85) for fixing the end portion (81) of the connector (82) of the wire device within the annular opening of the screwing guide core (55).

7. The screwing guide core (55) according to claim 6, wherein, the locking element (85) is configured to be connectable to a signal analyzer (86) via a cable (84) to transmit a signal from the coupling end (56) to the signal analyzer (86).

8. The screwing guide core (55) according to any one of claims 1 to 7, further including an end portion extending from the operating handle (83), and the signal analyzer (86) can be rotatably connected to the end portion via a cable (84) to transmit a signal from the coupling end (56) to the signal analyzer (86).

9. A wire system including the screwing guide core (55) according to any one of claims 1 to 8 and a wire device, the wire device including a wire end having a driver (52) configured to be able to engage the coupling end (56) of the screwing guide core when the screwing guide core (55) is inserted into the wire device.

10. A method of transmitting torque to a wire end of a wire device placed in a target area of a human or animal body, the method comprising: inserting a screwing guide core (55) into the wire device until the coupling end (56) of the screwing guide core (55) engages the driver (52) of the wire end; pushing an operating handle (83) fixed to a connector end opposite to the coupling end (56) of the screwing guide core (55), and due to elastic elongation of the wire body (54) of the wire device, a connecting force is generated between the coupling end (56) of the screwing guide core (55) and the driver (52); Lock the operating handle (83) to the wire body (54) using the locking element (85) of the operating handle (83) to maintain the connection force; and Rotate the screwing core (55) to transmit torque to the wire end via the driver (52).

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