Device to prevent mis-deployment of instruments

Abstract

A device that prevents misdeployment or damage to the moving parts of a therapeutic instrument via a force-limiting element located on the therapeutic instrument or between the therapeutic instrument and the device handle.

Description

[Technical Field]

[0001] The present invention relates generally to a device for preventing malapposition of moving parts of medical devices, and more particularly, therapeutic devices, where the moving parts are involved in treating tissue or anatomical structures within the body of a human or animal patient for the purpose of treating a disease or disorder. [Background technology]

[0002] Various diseases or disorders of soft tissues and anatomical organs, such as the uterus, intestine, and prostate, may require surgical intervention with a therapeutic device to treat or remove abnormal, diseased, hypertrophied, or overgrown tissue. When performing such procedures, a physician or surgeon may encounter non-target tissue, such as bone, calcifications, or other hard or solid anatomical structures, during the introduction or manipulation of the therapeutic device at the patient's intervention site, especially when the intervention site is located in close proximity to a soft-hard tissue interface.

[0003] One such intervention site, involving the soft-hard tissue interface, is the anatomical region defined by the prostatic urethra, prostate, and pelvic bones that is commonly accessed during prostatectomy procedures for the treatment of urinary diseases or disorders, such as benign prostatic hyperplasia (BPH). BPH is one of the most common conditions found in men, particularly older men. In the United States, by age 60, more than half of all men exhibit histopathological evidence of BPH, and by age 85, nearly 9 in 10 men suffer from the condition. Furthermore, the incidence and prevalence of BPH are expected to increase as the life expectancy of developed nations' populations increases.

[0004] The prostate gland enlarges throughout a man's life. In some men, the prostatic capsule around the prostate gland prevents further enlargement. This causes the inner region of the prostate to squeeze the urethra. This pressure on the urethra increases resistance to urine flow through the area of ​​the urethra surrounded by the prostate. Thus, the bladder must exert more pressure to expel urine due to increased urethral resistance. Chronic overexertion causes the muscular wall of the bladder to deform and stiffen. This increased urethral resistance to urine flow, combined with the stiffening and thickening of the bladder wall, results in a variety of lower urinary tract symptoms (LUTS) that can significantly reduce a patient's quality of life. These symptoms include a weak or interrupted urine stream during urination, straining to urinate, a feeling that the bladder is not completely empty after urination (residual urine), dribbling or leakage of urine at the end of urination, increased frequency of urination, especially at night, and a sense of urgency.

[0005] In addition to patients with BPH, LUTS can also occur in patients with prostate cancer, patients with prostate infections, and patients who chronically use certain medications (e.g., ephedrine, pseudoephedrine, phenylpropanolamine, antihistamines such as diphenhydramine, chlorpheniramine, etc.) that cause urinary retention, especially in men with benign prostatic hyperplasia.

[0006] Although BPH is rarely life-threatening, it can lead to a number of clinical morbidities, including urinary retention, renal failure, recurrent urinary tract infections, incontinence, hematuria, and bladder stones.

[0007] In developed countries, a large proportion of the patient population is treated for BPH symptoms. By age 80, approximately 25% of the male population in the United States has received some form of treatment for BPH. Currently, available treatment options for BPH include observation, medications (phytotherapy and prescription medications), surgery, and minimally invasive procedures.

[0008] For patients who choose the watch-and-wait option, they receive no immediate treatment but undergo regular checkups to monitor the progress of their disease, typically for patients with minimal, non-troublesome symptoms.

[0009] Surgical procedures to treat BPH symptoms include transurethral resection of the prostate (TURP), transurethral electrovaporation of the prostate (TVP), transurethral incision of the prostate (TUIP), laser prostatectomy, and open prostatectomy.

[0010] Minimally invasive procedures for treating BPH symptoms include transurethral microwave thermotherapy (TUMT), transurethral needle ablation (TUNA), interstitial laser coagulation (ILC), and prostatic stenting.

[0011] Many current methods for treating BPH carry a high risk of side effects. These methods and devices either require general or spinal anesthesia, or the procedures are performed in an operating room, resulting in potentially negative outcomes that require the patient to be hospitalized afterward. BPH treatment methods with a low risk of postoperative adverse effects are also associated with reduced symptom scores. While some of these procedures can be performed in an office setting with local analgesia, patients do not experience immediate relief and, in fact, often experience worsening symptoms for several weeks after the procedure as the body begins to heal. In addition, many device-based procedures require a urinary catheter to remain in the bladder, potentially for several weeks. In some cases, catheterization is necessary because the therapy actually causes blockage for a period of time after surgery, and in other cases, catheterization is indicated due to postoperative bleeding or the formation of potentially obstructive blood clots. Drug treatments are easy to administer, but often have limited results, require a significant amount of time to be effective, and are accompanied by unwanted side effects.

[0012] Novel devices and methods have been developed for various procedures to lift, compress, support, reposition, remove, or otherwise alter prostate tissue either separately or in combination with the treatment of BPH. Such devices and methods are disclosed in U.S. Patent Nos. 7,645,286, 7,758,594, 7,766,923, 7,905,889, 7,951,158, 8,007,503, 8,157,815, 8,216,254, 8,333,776, 8,343,187, and 8,394,110. , 8,425,535, 8,663,243, 8,715,239, 8,715,298, 8,900,252, 8,936,609, 8,939,996, 9,320,511, 9,549,739, 10,105,132, and 10,299,780, which are incorporated by reference in their entireties. During some procedures, the moving portion of the therapeutic instrument may encounter bone, calcifications, or other solid or hard anatomical structures, causing damage, such as breaking, bending, or buckling, to the moving portion or other components of the therapeutic instrument operatively connected to the moving portion. Such damage may prevent proper healing.

[0013] In addition to devices and methods for treating BPH, there are devices and methods for treating other conditions in which the therapeutic device uses movable parts to manipulate tissue or anatomical structures within the body of a human or animal patient for the purpose of treating a disease or disorder. Such methods and devices may encounter situations in which the movable part, or other parts of the therapeutic device operatively connected to the movable part, come into contact with solid or rigid anatomical structures, thereby damaging the movable part or preventing the intended treatment from proceeding as desired. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] U.S. Patent No. 7,645,286 [Patent Document 2] U.S. Patent No. 7,758,594 [Patent Document 3] U.S. Patent No. 7,766,923 [Patent Document 4] U.S. Patent No. 7,905,889 [Patent Document 5] U.S. Patent No. 7,951,158 [Patent Document 6] U.S. Patent No. 8,007,503 [Patent Document 7] U.S. Patent No. 8,157,815 [Patent Document 8] U.S. Patent No. 8,216,254 [Patent Document 9] U.S. Patent No. 8,333,776 [Patent Document 10] U.S. Patent No. 8,343,187 [Patent Document 11] U.S. Patent No. 8,394,110 [Patent Document 12] U.S. Patent No. 8,425,535 [Patent Document 13] U.S. Patent No. 8,663,243 [Patent Document 14] U.S. Patent No. 8,715,239 [Patent Document 15] U.S. Patent No. 8,715,298 [Patent Document 16] U.S. Patent No. 8,900,252 [Patent Document 17] U.S. Patent No. 8,936,609 [Patent Document 18] U.S. Patent No. 8,939,996 [Patent Document 19] U.S. Patent No. 9,320,511 [Patent Document 20] U.S. Patent No. 9,549,739 [Patent Document 21] U.S. Patent No. 10,105,132 [Patent Document 22] U.S. Patent No. 10,299,780 Summary of the Invention [Problem to be solved by the invention]

[0015] There is a need for a novel system that prevents damage to moving parts of a therapeutic instrument when the moving parts or other parts operatively connected to the moving parts strike non-target tissue or structures. The present invention addresses these needs. [Means for solving the problem]

[0016] SUMMARY OF THE INVENTION Embodiments of the present invention relate to an apparatus for preventing damage to therapeutic instruments for treating tissue or anatomical structures within a human or animal patient for the treatment of a disease or disorder.

[0017] An embodiment of the present invention includes an apparatus for reducing damage to a medical instrument, the apparatus having a medical tool coupled to a movable assembly at a proximal portion of the medical tool, the apparatus further having a force-limiting element coupled to the proximal portion of the medical tool and coupled to the movable assembly, the force-limiting element allowing movement of the proximal portion of the medical tool in a proximal direction relative to the movable assembly while maintaining coupling between the movable assembly and the proximal portion of the medical tool even when the force experienced by the medical tool increases up to a predetermined force magnitude.

[0018] In some embodiments, the force-limiting element comprises a spring, a reversibly engagable connector, or both. In some embodiments, the predetermined amount of force is the amount of force required to extend the spring. In some embodiments, the predetermined amount of force is the amount of force required to disengage the reversibly engagable connector.

[0019] In some embodiments, the proximal portion of the treatment tool further comprises a friction element that conditionally prevents movement of the proximal portion of the treatment tool relative to the movable assembly, hi some embodiments, the force-limiting element assists in moving the proximal portion of the treatment tool in a distal direction relative to the movable assembly when the force experienced by the treatment tool decreases below a predetermined force magnitude.

[0020] In some embodiments, the treatment tool is a suture or a needle.

[0021] In some embodiments, the device further comprises an indicator that indicates when the treatment tool is fully deployed, hi some embodiments, the indicator comprises a visual, audio, or tactile indicator.

[0022] Other features and advantages of embodiments of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, certain principles of the invention. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is an exploded isometric view of a handle of a system for treating benign prostatic hyperplasia. [Figure 2A] 1 is an isometric view of a cartridge of a system for treating benign prostatic hyperplasia. [Figure 2B] FIG. 2B is an enlarged isometric view of the cartridge housing assembly of the cartridge of FIG. 2A. [Figure 3A] FIG. 1 is an isometric view of a force-limiting assembly according to an embodiment of the present invention. [Figure 3B] FIG. 1 is an isometric view of a force-limiting assembly according to an embodiment of the present invention. [Figure 4] 1 is an isometric view of a portion of a force-limiting assembly according to an embodiment of the present invention. [Figure 5A] FIG. 10 is a plan view of a force-limiting assembly according to another embodiment of the present invention. [Figure 5B] FIG. 10 is a plan view of a force-limiting assembly according to another embodiment of the present invention. [Figure 6] FIG. 10 is an isometric view of a force-limiting connector according to another embodiment of the present invention. [Figure 7] FIG. 10 is an isometric view of a handle-cartridge system including a deployment indicator according to another embodiment of the present invention. [Figure 8] FIG. 10 is a side view of a section of a handle having a deployment indicator according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Many specific details are described herein to provide a thorough understanding of the claimed subject matter. However, as will be understood by those skilled in the art, the claimed subject matter may be practiced without these specific details. In other instances, methods, apparatus, or systems that would be known by those skilled in the art have not been described in detail so as not to obscure the claimed subject matter.

[0025] As used herein, the phrases "adapted to" or "configured to" are to be considered open-ended and inclusive language that does not exclude instruments adapted or configured to perform additional tasks or steps. As used herein, the terms "proximal" and "distal" refer to the relative location of an elongated minimally invasive instrument with respect to a user, with "proximal" meaning closer to the user and "distal" meaning farther from the user. The headings, listings, and numbering used herein are for ease of description only and are not meant to limit the invention.

[0026] Generally, embodiments of the present disclosure or devices of the present invention prevent damage to the therapeutic instrument. The therapeutic instrument delivered to the patient's intervention site may include a variety of tools to treat, remove, or otherwise alter tissue. Such tools include, but are not limited to, needles, cutting blades, vacuum devices, grasping arm assemblies, expandable cutting members, blunt dissectors, nooses or ligation clips, articulating heads with integral or retractable blades, helical blades, radiofrequency energy delivery electrodes, cutting wires or rings, electrocautery probes, or staple or suture delivery heads. These tools may be advanced from the working channel, needle, or piercing element to the distal end of the therapeutic instrument's elongate member, thereby allowing the tool to be withdrawn from the elongate member. In some embodiments, the tool may be attached to the distal end of the elongate member, and the tool does not require withdrawal.

[0027] Referring now to the figures, which are provided by way of illustration and not limitation, embodiments of the present invention relate to devices that limit and / or attenuate forces applied to moving portions of a therapeutic instrument. Certain embodiments of the present invention additionally or alternatively relate to devices that accommodate relative changes in length between two moving portions of a therapeutic instrument as they move relative to one another. In many cases, embodiments of the present invention can prevent damage to moving portions of a therapeutic instrument while the therapeutic instrument is being used to treat tissue or anatomical structures within a human or animal patient for the treatment of a disease or disorder. The disclosed devices can be embodied in a variety of therapeutic instruments employed for a variety of medical purposes, including, but not limited to, retracting, lifting, compressing, approximating, supporting, reshaping, repositioning, removing, or otherwise altering tissue, organs, anatomical structures, grafts, or other objects found within a human or animal patient. In certain embodiments, the treatment device is adapted to displace, compress, retract, or destroy prostate tissue to facilitate treatment of a disease or disorder, such as benign prostatic hyperplasia (BPH).

[0028] 1, an exploded isometric view of a BPH treatment instrument handle 100 is shown. The BPH treatment instrument handle 100 has a right handle case 101, a left handle case 102, and a cartridge bay 103 formed within the left handle case 102. The treatment instrument handle 100 is designed to transfer energy stored in several springs within the treatment instrument handle 100 to a cartridge (shown in FIG. 2A) to enable treatment of BPH within a patient.

[0029] The treatment instrument handle 100 includes a handle trigger assembly 110 operatively coupled to a handle trigger spring 111 such that the handle trigger spring 111 provides sufficient force to return the handle trigger assembly 110 to its initial position after the handle trigger assembly 110 is squeezed and released by a user. A ratchet 114 coupled to a ratchet spring 115 influences the movement of the handle trigger assembly 110 so that the handle trigger assembly 110 does not return to its initial position before being squeezed a predetermined amount by the user. A safety 112 is coupled to the handle trigger assembly 110 to prevent accidental actuation of the handle trigger assembly 110. The handle trigger assembly 110 is coupled to a drive gear 113, which is coupled to a cam wheel 120.

[0030] The cam wheel 120 rotates about a central axis, and as the cam wheel 120 rotates, it triggers certain movements within the treatment instrument handle 100 via structures and features on the cam wheel. Multiple sleds are provided that are operatively connected to the cam wheel 120 and move linearly along the lateral axis of the treatment instrument handle 100. Multiple springs are provided that exert forces on the multiple sleds to cause the movements and provide sufficient mechanical energy to deliver implants for treating BPH. A cartridge (shown in FIG. 2A) has multiple tab assemblies that mate with the sleds via slots in the sleds, such that movement and energy imparted by actuation of mechanisms (e.g., springs) within the handle are transferred to mechanisms within the cartridge.

[0031] Specifically, implant trigger 121 is operatively connected to cam wheel 120 and implant sled 160, which is connected to implant spring 161, which provides the energy associated with delivering or transporting the implant. Needle sled 140 is operatively connected to cam wheel 120, with needle sled spring 141 providing the energy associated with delivering the implant. Suture sled 150 is operatively connected to cam wheel 120, with suture sled spring 151 providing the energy associated with delivering the implant. In each of these cases, the sled moves with sufficient velocity that instrument damage may result if the portion of the system connected to the sled strikes non-target hard tissue or other hard obstacle.

[0032] The treatment instrument handle 100 has various other components, such as a cover plate 130, an endoscope tube 131, a scope lock 170, a sheath lock 180, and various screws and / or fasteners for assembling the handle. The cover plate 130 provides an internal base for the cartridge bay 103. The endoscope tube 131, the scope lock 170, and the sheath lock 180 function to attach an endoscope and other ancillary equipment (e.g., a surgical sheath) to facilitate the procedure.

[0033] 2A, an isometric view, a cartridge 200 is configured to mate with a treatment instrument handle 100. A cartridge housing assembly 201 fits within the cartridge bay 103 of the treatment instrument handle 100, with the cartridge's elongated assembly 280 extending parallel to the endoscope tube 131 of the treatment instrument handle 100. A distal portion 285 of the elongated cartridge assembly 280 includes a needle exit port, which is configured to facilitate implant placement. Thus, the treatment instrument handle 100 and cartridge 200 together form a system for deploying an implant to treat BPH. A spring and sled in the treatment instrument handle 100 transfer energy and motion to a tab assembly within the cartridge housing assembly 201, advancing the needle into tissue and deploying the implant.

[0034] Region X of Figure 2A is shown in an enlarged isometric view in Figure 2B. Cartridge housing assembly 201 includes needle tab assembly 240, suture tab assembly 250, and implant tab assembly 260. These tab assemblies interact with sleds and springs within the treatment instrument handle to deliver the implant for the treatment of BPH. Linear motion of these tab assemblies translates to mechanical motion at and, in some cases, beyond the distal portion 285 of cartridge elongate assembly 280. For example, linear motion of needle tab assembly 240 is associated with movement of the penetrating needle from within distal portion 285 of cartridge elongate assembly 280 into tissue, and further linear motion of needle tab assembly 240 is associated with retraction of the penetrating needle from tissue back into distal portion 285 of cartridge elongate assembly 280. Similarly, linear movement of the suture tab assembly 250 is associated with movement of the implant from within the distal portion 285 of the cartridge elongate assembly 280 into tissue, and further linear movement of the suture tab assembly 250 is associated with deployment of the implant into tissue. Additionally, linear movement of the implant tab assembly 260 is associated with assembly of the implant within tissue, including severing sutures that are part of the implant.

[0035] The implant is deployed into tissue by relative movement of the needle tab assembly 240 and the suture tab assembly 250. As a first step, the needle tab assembly 240 and the suture tab assembly 250 move together in the distal direction at the same speed. That is, the needle tab assembly 240 and the suture tab assembly 250 maintain their relative positions relative to one another. As they move together, the needle tab assembly 240 and the suture tab assembly 250 advance the penetrating needle and implant to a location within the patient's tissue. The implant is coupled to a suture, and the suture is coupled to a suture tube connected to the suture tab assembly 250. During this first step, it is important that the needle tab assembly 240 and the suture tab assembly 250 maintain their relative positions relative to one another so that the implant maintains its position within the needle and can be deployed from the needle. The needle and the implant therein advance from the distal portion 285 of the cartridge elongate assembly 280 .

[0036] In a second step, the needle tab assembly 240 moves proximally while the suture tab assembly 250 is held in its distal position. This relative movement of the needle tab assembly 240 relative to the suture tab assembly 250 retracts the needle and deploys the implant. In a third step, the suture tab assembly 250 is retracted to position the implant and apply tension to the sutures connected to the implant. In a fourth step, the implant tab assembly 160 moves distally to attach the proximal components to the sutures to complete the implant and cut the sutures, thereby fully deploying the implant.

[0037] Movement of the needle tab assembly 240, suture tab assembly 250, and implant tab assembly 260 is achieved by interaction of these tab assemblies with springs and sleds within the instrument handle that cooperate with cam wheels and other features within the instrument handle to move the tab assemblies according to the steps disclosed herein.

[0038] The tab assemblies disclosed herein are coupled to elements that extend along all or a portion of the cartridge elongate assembly 280. For example, the needle tab assembly is coupled to a needle, and the suture tab assembly is coupled to a suture, with the needle and suture configured to allow at least a portion of the needle and at least a portion of the suture to extend through the distal portion 285 of the cartridge elongate assembly 280 and into tissue. The needle tab assembly may or may not be directly coupled to the needle, and the suture tab assembly may or may not be directly coupled to the suture. That is, one or more intermediate structures may be provided that interconnect the portions of the needle and / or suture that extend through the distal portion 285 of the cartridge elongate assembly 280 and into tissue. For example, the suture may be connected to the suture tab assembly via a suture tube, which may be made of a material that is relatively stiffer than the suture to allow transmission of compressive force along the relatively flexible suture. As another example, the needle may be connected to the needle tab assembly by an overmolded section, which may be made of a less expensive material than the distal portion of the needle. Thus, the connections between the tab assemblies and elements at the distal end of the cartridge elongate assembly may include tubes, overmolded sections, or equivalent intermediate sections.

[0039] In some embodiments, the fixed connection between the tab assembly and other features of the cartridge and implant may result in certain undesirable consequences. In certain circumstances, relative motion between the cartridge and implant features may be impaired, resulting in incomplete delivery or transport of the implant. For example, the needle may strike non-target tissue, such as bone, as the needle advances from the distal portion 285 of the cartridge elongate assembly 280. In this situation, the needle may bend or even buckle when it strikes the bone. If the needle bends or buckles, the relative position of the end of the needle and the implant within the needle may change due to high frictional forces generated by the bent or buckled needle.

[0040] In normal implant delivery situations, the friction between the inner surface of the needle and the outer surface of the implant is balanced by a spring force transmitted from the suture sled spring through the suture sled and into the suture tab assembly. This balance of friction and spring force keeps the implant and suture in the same position relative to the end of the needle. However, if the needle is bent or buckled, the friction force may increase such that it exceeds the spring force. In this case, the needle is retracted by the needle tab assembly, and this large friction force prevents the implant from deploying from the end of the needle. That is, the friction force partially exceeds the spring force, and the implant moves proximally with the retracting needle, thus preventing it from fully exiting the end of the needle. In other cases, the end of the needle may become blocked, preventing the implant from exiting the distal end of the needle.

[0041] One possible consequence of frictional forces being greater than spring forces is damage at or near the proximal end of the suture. For example, while the suture and coupled implant move proximally with the retracting needle as described above, the proximal end of the suture remains fixed by the suture tab assembly. Because the proximal end of the suture remains fixed while the distal end of the suture moves proximally, the proximal end of the suture may buckle or otherwise become damaged. Such damage may interfere with another attempt at implant deployment. That is, if the suture were not damaged, the needle could be retracted, the treatment instrument repositioned, and the needle deployed again, avoiding non-target tissue resulting in a failed deployment. However, damage to the proximal end of the suture at or near the suture tab assembly may prevent the suture tab assembly from functioning properly during the next deployment attempt. Thus, it is useful to vary the connection between the suture and the suture tab assembly to accommodate situations where increased friction at the distal end of the suture causes the suture and coupled implant to move proximally with the retracting needle. More generally, it is useful to provide a connection between a spring-loaded mechanical element of the system and an element driven by that spring-loaded force when such driven element encounters high friction or an obstacle that prevents movement.

[0042] 3A and 3B are isometric views of a force-limiting assembly according to an embodiment of the present invention. In this embodiment, the force-limiting assembly is configured to modify a suture tab assembly as provided herein. However, the force-limiting aspects of this force-limiting assembly may also be configured to modify a needle tab assembly, an implant tab assembly, or other assembly, where the force-limiting aspects are useful for preventing damage to elements being rapidly moved by spring or other forces. In FIGS. 3A and 3B, a suture tab assembly 350 includes a suture tab assembly connection block 352, which is a connection region for a suture tube 351. A proximal end portion 355 of the suture tube is coupled to the suture tab assembly connection block 352 and to a force-limiting spring 356. As shown in FIG. 4, the suture tab assembly connection block 352 can include a suture tab connection block passage 353. 3A and 3B, the suture tube proximal end portion 355 extends through the suture tab connection block passage 353 as one way of coupling the suture tube 351 to the suture tab assembly 350. While the suture tab connection block passage 353 is provided as a hole in the suture tab assembly connection block 352, other similar configurations are within the scope of the present invention. The suture tab connection block passage 353 functions to couple the suture tube 351 to the suture tab assembly 350 while still allowing the force-limiting spring 356 to function in certain circumstances. Other coupling configurations for coupling the suture tube 351 to the suture tab assembly 350 while allowing the force-limiting spring 356 to function in certain circumstances can be utilized.

[0043] Force-limiting spring 356 is joined to suture tube proximal end portion 355 and to suture tab assembly 350. In Figures 3A and 3B, force-limiting spring 356 is shown joined to suture tab assembly 350 at suture tab assembly coupling block passage 352. However, force-limiting spring 356 may be joined to any portion of suture tab assembly 350, provided that force-limiting spring 356 is configured to perform the force-limiting function disclosed herein. Similarly, force-limiting spring 356 may be joined to suture tube 351 at any location, provided that force-limiting spring 356 is configured to perform the force-limiting function disclosed herein. Although force-limiting spring 356 is shown in Figures 3A and 3B as a coil-type spring, other types of springs may be employed, provided that such springs are configured to function as force-limiting springs as disclosed herein.

[0044] 3A and 3B show that the force-limiting spring 356 is a tension spring whose coils create a lumen through which the suture tube 351 passes. The ends of such a tension spring may have hooks or loops, such as, but not limited to, mechanical hooks, crossover center hooks, side hooks, offset saturation hooks, V-hooks, elongated hooks, rectangular hooks, single or multi-twist loops, open or closed loops, center loops, or side loops. In other embodiments, the force-limiting spring 356 is a leaf spring or other spring mechanism. Certainly, the force-limiting spring 356 is used for purposes of illustration to mean that the force-limiting spring 356 is a mechanism that can accommodate proximal movement of the suture tube and then assist in returning the suture tube to its initial position.

[0045] FIG. 3A shows the suture tab assembly 350 with the force-limiting spring 356 in a relaxed position. In this position, the force-limiting spring 356 is not acting to limit any force applied to the suture tube 351. FIG. 3B shows the suture tube assembly 350 with the force-limiting spring 356 in an extended position. The force-limiting spring 356 is in an extended state due to an increased frictional force on the distal end of the suture. The increased frictional force may be due to a bent or buckled needle or a restriction on the distal end of the needle, preventing the implanted and coupled suture from extending the needle when the needle tab assembly is retracted. That is, forces are transmitted from the proximal side to the suture tab assembly 350 further distally on the suture. These transmitted forces accommodate the force-limiting spring 356, which extends in a manner to absorb the transmitted forces. In this way, the relative positions of the implant and the connected suture and the distal end of the needle are maintained in situations where these positions would otherwise change due to increased friction and / or blockage at the distal portion of the needle.

[0046] Thus, the spring force can be considered a predetermined force that friction forces must overcome in order for the force-limiting spring to perform its force-limiting behavior. Force-limiting springs can be said to follow Hooke's Law, such that the spring force scales linearly with the spring extension length. Force-limiting springs can also be so-called "constant force" springs, where the spring force is approximately constant even with relatively small variations about the initial preload position.

[0047] 5A and 5B are plan views of a force-limiting assembly according to another embodiment of the present invention. In this embodiment, suture tube 351 has a friction element 358 near the area where suture tube 351 is coupled to suture tab assembly connection block 352. In some embodiments, friction element 358 is a collar or similar structure that conditionally prevents suture tube 351 from moving proximally through suture tab assembly connection block 352 and engaging force-limiting spring 356. In some embodiments, friction element 358 is a flattened or crimped section of suture tube 351 such that the cross-section of suture tube 351 at friction element 358 is wider in at least one radial direction than the remainder of suture tube 351.

[0048] The conditional nature of friction element 358 is such that a minimum amount of force is required to push friction element 358 through suture tab coupling block passage 353. That is, the force experienced by the suture or suture tube as a result of the needle bending or buckling, or the distal end of the needle becoming blocked, must be greater than the force required to push friction element 358 through suture tab coupling block passage 353. Thus, there are embodiments in which the restoring force of force limiting spring 356 is sufficient to balance the forces experienced by the suture and / or suture tube, and in such embodiments, a friction element is not required. However, there are also embodiments in which the use of a friction element is useful or necessary to balance the forces experienced by the suture and / or suture tube, while still preventing undesired engagement of the friction limiting spring.

[0049] In this regard, the suture tab interface block passage 353 serves as a snug fit for the friction element 358. The width of the friction element 358 is selected to allow the friction element 358 to pass through the suture tab interface block passage 353 when sufficient force is applied either to the distal end of the suture tube (e.g., when the needle strikes bone or other hard material) or to the proximal end of the suture tube (e.g., when the force limiting spring 356 is returned to its initial position). The friction element 358 may also be calibrated based on the location and physical properties of non-target tissue that may be encountered during use of the treatment device at the patient's intervention site.

[0050] Some of the embodiments disclosed herein utilize a force-limiting spring to assist in returning the suture tube to its initial position. In this case, proper deployment of the implant can be attempted using a reset handle-cartridge system. Other embodiments provide a mechanism for increasing and / or inhibiting friction at the distal end of the needle, allowing the suture tube to be manually returned to its initial position. In some embodiments, such a system can be returned to its initial position by an actuator or trigger on the handle of the system.

[0051] In FIG. 6 , suture tab assembly 450 includes suture tab assembly connection block 452, which is the connection region for suture tube 451. Suture tube proximal end portion 455 is coupled to suture tab assembly connection block 452 and to force-limiting connector 456. Force-limiting connector 456 has a latch 458 configured to reversibly engage notch 459. FIG. 6 illustrates the latch 458 disengaging from notch 459 as a result of an increase in force on suture tube 451 to a degree that is greater than the engagement force of latch 458 with notch 459. Thus, in this embodiment, the engagement force between latch 458 and notch 459 maintains the position of suture tube 451 until the force on suture tube 451 increases to a degree that risks damage to the suture and / or suture tube. After the latch 458 disengages from the notch 459, the implant deployment instrument can be manually moved to a position that resets the suture tab assembly 450 and re-engages the latch 458 with the notch 459. From this reset position, proper deployment of the implant can be attempted.

[0052] In some embodiments disclosed herein, the handle-cartridge system is designed to function properly and deliver the implant when the needle has moved a desired distance beyond the distal portion of the distal end of the cartridge elongate assembly. Similarly, the handle-cartridge system is designed to function properly and deliver the implant when the needle and implant maintain a desired relative position during a step in the implantation process. The force-limiting spring and force-limiting connector disclosed herein help prevent damage to elements within the cartridge-handle system if the system is not functioning in a manner that allows the system to successfully deliver the implant.

[0053] According to certain aspects of the embodiments disclosed herein, the handle cartridge system includes a position indicator that alerts the user to certain conditions that may prevent the handle cartridge system from successfully delivering the implant. FIG. 7 is an isometric view of a handle cartridge system similar to those shown in FIGS. 1 and 2A. A cartridge 800 is shown inserted and engaged with the handle 700. The left handle case 702 has a front opening within which a needle sled button 745 travels. The needle sled button 745 is coupled to a needle sled (e.g., needle sled 140 shown in FIG. 1) within the handle 700. The needle sled button 745 is configured to tactilely indicate the presence of the front opening in the left handle case 702 when the needle sled 140 is in the proximal position and the cartridge needle is undeployed. When the needle sled 140 has moved sufficiently forward to deploy the needle to its full extent from the distal end portion of the cartridge elongate assembly, the needle sled button 745 moves forward within the front opening of the left handle case 702 so that the needle sled button 745 is flush with the entire surface of the left handle case 702. In this configuration, a user can tactilely sense that the front opening of the left handle case 702 is completely filled with the needle sled button 745.

[0054] If the needle is not fully deployed from the distal end of the cartridge elongate assembly to its full deployment extent, the needle sled button 745 will not fully fill the front opening of the left handle casing 702. In this case, the user will have a tactile indication that the needle is incompletely deployed, and the user can take steps to reset the instrument and attempt deployment again. Thus, the needle sled button 745 provides another mechanism to reduce or prevent damage to the needle, implant, suture, or other mechanisms within the handle-cartridge system.

[0055] In another embodiment, the needle sled has a mechanism to visually or audibly alert the user that the needle is not fully deployed or that the needle is fully deployed. For example, referring again to FIG. 8 , cover plate 830 (similar to cover plate 130 of FIG. 1 ) is modified to have a mounting post for a hemispherical bell 834. Cover plate 830 also has a feature for mounting ringer spring 832. Ringer spring 832 protrudes into the interior of bell 834 (this configuration saves space compared to a bell striker that is externally attached to the bell). Needle sled 840 is modified to have an alert arm 836 that contacts ringer spring 832 as needle sled 840 moves distally during the needle deployment step, as described elsewhere herein. Alert arm 836 causes ringer spring 832 to flex as it passes under bell 834. That is, alert arm 836 folds over ringer spring 832 as alert arm 836 moves distally. Alert arm 836 is configured to release ringer spring 832 when needle sled 840 moves distally to a position consistent with full needle deployment. The released ringer spring 832 pops up and strikes bell 834, thereby notifying the user that the needle is fully deployed. Thus, if the user does not hear the bell, the user can take steps to reset the system and redeploy the needle. To prevent bell 834 from ringing again when needle sled 840 is redeployed to its initial position and at the end of the deployment sequence, alert arm 836 has a ramp feature that temporarily moves ringer spring 832 aside instead of collapsing it. Moving the ringer spring 832 aside allows it to return to its original position without ringing the bell 834. One advantage of this design is that it is insensitive to the speed of the needle sled. Because the force used to strike the bell is the force generated by the spring in its folded state, a slow moving sled or a fast moving sled will produce the same amount of audible signal.

[0056] The embodiments disclosed herein include aspects that indicate full needle deployment and / or incomplete needle deployment. There are aspects of the embodiments that prevent damage to the needle assembly or suture assembly and allow for manual reset. There are aspects of the embodiments that prevent damage to the needle assembly or suture assembly and assist in resetting the device. Each of these aspects can be used in combination with one another when their use is compatible. For example, embodiments can be envisioned that include a deployment indicator and also include a force-limiting feature. Such a force-limiting feature can be said to allow for manual reset, automatic reset, or both. The separate description of embodiments does not exclude their combined use.

[0057] Other therapeutic instruments can benefit from the use of the embodiments disclosed herein. Therapeutic instruments with a variety of tools that treat, remove, or otherwise alter tissue (such tools being powered, deployed, or driven by mechanical energy) can benefit from the use of the force-limiting springs and connectors disclosed herein and the use of the deployment indicators disclosed herein. Such tools include, but are not limited to, needles, cutting blades, vacuum devices, grasper arm assemblies, expandable cutting members, blunt dissectors, nooses or ligation clips, articulating heads with integral or retractable blades, helical blades, radiofrequency energy delivery electrodes, cutting wires or rings, electrocautery probes, or staple or suture delivery heads.

[0058] In some embodiments, the treatment instrument can include an introducer with a lumen carrying the tool and a handle assembly coupled to the introducer, the treatment instrument having a pusher, sled, or delivery mechanism that moves the tool forward, thereby extracting it from the distal end of the introducer, which can be accomplished by an actuator or trigger on the handle assembly.

[0059] In certain embodiments, the treatment instrument can be a device that deploys one or more implants to retract, lift, compress, support, reshape, or reposition tissue within a patient. The treatment instrument can deliver a first or distal anchor component toward a first location within the patient and a second or proximal anchor component to a second location within the patient. The treatment instrument can also apply tension to connectors that attach the first and second anchors.

[0060] In some embodiments, the treatment instrument includes a cartridge carrying at least one implant and a handle configured to receive the cartridge. The handle includes an actuator and at least one spring mechanism to which mechanical energy is applied. The handle further includes a member that mates with the cartridge and transfers mechanical energy from the spring mechanism to the cartridge to deploy the implant. The handle-cartridge system includes a first firing sled with a slot that aligns with a pusher tab on the needle assembly. The slot on the first firing sled and the pusher tab on the needle assembly are complementary mechanisms that can transfer energy from the spring mechanism through the first firing sled to fire the needle in the cartridge. The handle-cartridge system may further include a second firing sled with a slot that aligns with a pusher tab on the suture tube or connector tube. The slots in the second firing sled and the pusher tabs on the suture tube are complementary mechanisms that allow energy to be transferred from the spring mechanism through the second firing sled to advance the suture tube simultaneously with the needle tube.

[0061] Other therapeutic instruments may further utilize moving parts employing mechanical energy to introduce the tool into the intervention site. If the tool strikes bone, calcification, or other solid or hard anatomical structure, this may cause damage to the tool and / or moving parts within the therapeutic instrument. In some cases, no damage to the tool or moving parts may occur, but tool deployment may be unsuccessful if the tool strikes such non-target tissue.

[0062] A device that prevents or at least reduces malapposition of a needle, penetrating member, or other tool due to striking bone (or striking other non-target tissue) can include an adjustable, compressible, extendable, or resettable element coupled to a moving part within the treatment instrument. In some embodiments, for example, if the treatment instrument has a connector or tensioning element, the device can prevent or at least reduce buckling of the connector due to striking bone.

[0063] While particular elements, embodiments and applications of the present invention have been illustrated and described, it will be understood that the invention is not limited thereto, as modifications can be made by those skilled in the art without departing from the scope of the present invention, particularly in light of the above teachings.

Claims

1. 1. An apparatus for reducing damage to a treatment tool, comprising: a treatment tool having a proximal portion disposed to pass through a passage formed in a portion of a movable assembly, the movable assembly moving at least a portion of the treatment tool by linear motion thereof, the treatment tool having a suture tube at its proximal portion; a force-limiting element coupled to the suture tube and coupled to the movable assembly, the proximal end of the force-limiting element being coupled to the proximal end of the suture tube and the distal end of the force-limiting element being coupled to the movable assembly; The force-limiting element allows the suture tube to move in a proximal direction relative to the movable assembly when a force acting on the distal portion of the suture tube from its axial distal side toward its axial proximal side increases to a predetermined force magnitude, and the proximal end of the force-limiting element is joined to the proximal end of the suture tube so as to move in a proximal direction together with the proximal end of the suture tube to prevent damage to the proximal end of the suture tube when the force acting on the distal portion of the suture tube increases to the predetermined force magnitude.

2. The device described in claim 1, wherein the movable assembly comprises a suture tab assembly including a connecting block to which the suture tube is connected, and the force-limiting element comprises a spring joined to the proximal end of the suture tube and joined to the suture tab assembly.

3. The device of claim 1 , wherein the force-limiting element comprises a latch configured to reversibly engage the movable assembly.

4. The device of claim 1 , wherein the force-limiting element comprises both a spring and a latch configured to reversibly engage the movable assembly.

5. 3. The device of claim 2, wherein the spring is an extension spring, and the predetermined magnitude of force is the magnitude of force required to extend the extension spring from an initial position, which is a relaxed position, to an extended position where the frictional force acting on the distal end of the treatment tool becomes greater than the spring force.

6. 4. The device of claim 3, wherein the predetermined magnitude of force is a magnitude of force required for the force applied to the distal end of the treatment tool to exceed the engagement force of the latch with the movable assembly, causing the latch to disengage from the movable assembly.

7. The device of claim 1 , wherein the proximal portion of the treatment tool further comprises a friction element that conditionally prevents movement of the proximal portion of the treatment tool relative to the movable assembly.

8. The device of claim 1 , wherein the force-limiting element assists in moving the proximal portion of the treatment tool in a distal direction relative to the movable assembly when the force experienced by the treatment tool decreases from a state where the force is equal to or greater than a predetermined magnitude to a state where the force is less than the predetermined magnitude.

9. The device of claim 1 , wherein the treatment tool further comprises a suture coupled to the suture tube.

10. The device of claim 1, wherein the movable assembly includes a suture tab assembly to which the suture tube is connected and a needle tab assembly that maintains a relative position with the suture tab assembly, and the treatment tool further includes a needle connected to the needle tab assembly.

11. 11. The device of claim 10, further comprising a needle sled button that is tactilely identifiable as indicating that the needle is undeployed.

12. 11. The device of claim 10, further comprising a needle sled that provides a visual or audible indication to a user that the needle is in an undeployed state.

13. 1. A device for reducing the risk of damage to a treatment tool, comprising: a treatment tool advanceable from a treatment instrument handle, wherein linear movement of at least one tab assembly of the treatment instrument handle moves at least a portion of the treatment tool, the treatment tool including a suture tube at a proximal portion thereof; a restricting element configured to connect the suture tube to the treatment instrument handle, the proximal end of the restricting element being connected to the suture tube and the distal end of the restricting element being connected to the at least one tab assembly of the treatment instrument handle, the restricting element being configured to engage with the suture tube, and when a force greater than a predetermined magnitude is applied to a distal portion of the suture tube in an axial direction from its distal side to its proximal side with the restricting element engaged with the suture tube, the proximal end of the restricting element remains engaged with the suture tube and moves in a proximal direction with the suture tube.

14. The device of claim 13 , wherein the restricting element acts to allow proximal movement of the proximal portion of the treatment tool when the distal portion of the treatment tool contacts non-target tissue.

15. The device of claim 14 , wherein the non-target tissue is bone.

16. The device of claim 13 , wherein the restricting element is further configured to move the treatment tool distally.

17. The device of claim 13, wherein the tab assembly includes a suture tab assembly to which the suture tube is connected and a needle tab assembly that maintains the relative position of the suture tab assembly, the treatment tool further includes a needle connected to the needle tab assembly, and the device further includes a needle sled button that can be tactilely recognized to indicate that the needle is in an undeployed state.

18. The device of claim 13, wherein the tab assembly comprises a suture tab assembly to which the suture tube is connected and a needle tab assembly that maintains a relative position with the suture tab assembly, the treatment tool further comprises a needle connected to the needle tab assembly, and the device further comprises a needle sled that visually or audibly indicates to the user that the needle is undeployed.

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