Apparatus for preventing device deployment failure

Abstract

To provide an apparatus for preventing device deployment failure.SOLUTION: An apparatus for preventing deployment failure or damage of a movable portion of a treatment device via a force limiting element disposed in the treatment device or between the treatment device and an apparatus handle.SELECTED DRAWING: Figure 3B

Description

[Technical field]

[0001] The present invention relates generally to a device for preventing malapposition of moving parts of medical instruments, and in particular therapeutic instruments, 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, enlarged, or overgrown tissue. When performing such procedures, the physician or surgeon may encounter non-target tissue, such as bone, calcifications, or other hard or solid anatomical structures, during 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 urological diseases or disorders, such as Benign Prostatic Hyperplasia (BPH). BPH is one of the most common conditions found in men, especially older men. In the United States, by age 60, over half of all men will have histopathological evidence of BPH, and by age 85, nearly 9 in 10 men will suffer from the condition. Furthermore, the incidence and prevalence of BPH is expected to increase as the life expectancy of the developed world's population increases.

[0004] The prostate gland enlarges throughout a man's life. In some men, the prostatic capsule around the prostate gland may prevent further enlargement of the prostate. This causes the medial region of the prostate to squeeze the urethra. This pressure on the urethra increases the resistance to urine flow through the area of ​​the urethra surrounded by the prostate. Thus, the bladder must exert more pressure to push urine out due to the increased resistance of the urethra. Chronic overexertion causes the muscular walls of the bladder to deform and become stiff. This increased resistance of the urethra 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 urinary stream during urination, straining to urinate, hesitating before the urinary stream begins, a feeling that the bladder is not completely empty after urination (residual urine), dribbling at the end of urination or leaking urine afterwards, 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, phenylpropanolamines, 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 result in 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, medical treatment (phytotherapy and prescription drugs), surgery, and minimally invasive procedures.

[0008] For patients who choose the watch and wait option, they are not given any immediate treatment but undergo regular check-ups to monitor the progress of the disease. This is usually done for patients with minimal symptoms that are not particularly bothersome.

[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 stent placement.

[0011] Many current methods of treating BPH have 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, with potentially negative effects that require the patient to be hospitalized afterwards. Methods of treating BPH with a low risk of postoperative adverse effects are also associated with reduced symptom scores. Although 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 until 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 obstruction for a period of time after surgery, and in other cases, catheterization is indicated due to postoperative bleeding and potentially obstructive clot formation. Drug therapy is easy to administer, but the results are modest, require a significant amount of time to be effective, and are often accompanied by undesirable side effects.

[0012] Novel devices and methods have been developed for a variety of procedures to lift, compress, support, reposition, remove, or otherwise alter prostate tissue either separately or in combination with the treatment of BPH, including, but not limited to, 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. Nos. 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 herein by reference in their entirety. During some procedures, the moving part of the therapeutic instrument may strike bone, calcifications, or other solid or hard anatomical structures, causing damage, such as breakage, bending, or buckling, to the moving part or other components of the therapeutic instrument operatively connected to the moving part. 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. Pat. No. 7,905,889 [Patent Document 5] U.S. Pat. No. 7,951,158 [Patent Document 6] U.S. Pat. No. 8,007,503 [Patent Document 7] U.S. Pat. No. 8,157,815 [Patent Document 8] U.S. Pat. No. 8,216,254 [Patent Document 9] U.S. Pat. No. 8,333,776 [Patent Document 10] U.S. Pat. No. 8,343,187 [Patent Document 11] U.S. Pat. No. 8,394,110 [Patent Document 12] U.S. Patent No. 8,425,535 [Patent Document 13] U.S. Pat. No. 8,663,243 [Patent Document 14] U.S. Pat. No. 8,715,239 [Patent Document 15] U.S. Pat. No. 8,715,298 [Patent Document 16] U.S. Patent No. 8,900,252 [Patent Document 17] U.S. Pat. No. 8,936,609 [Patent Document 18] U.S. Pat. No. 8,939,996 [Patent Document 19] U.S. Patent No. 9,320,511 [Patent Document 20] U.S. Pat. No. 9,549,739 [Patent Document 21] U.S. Pat. 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 exists a need for a novel system for preventing 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 DISCLOSURE 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 treatment instrument, the apparatus having a treatment tool coupled to a moveable assembly at a proximal portion of the treatment tool, the apparatus further having a force-limiting element coupled to the proximal portion of the treatment tool and coupled to the moveable assembly, the force-limiting element allowing movement of the proximal portion of the treatment tool in a proximal direction relative to the moveable assembly while maintaining coupling between the moveable assembly and the proximal portion of the treatment tool even when the force experienced by the treatment 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 moveable 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 moveable assembly when the force experienced by the treatment tool decreases below a predetermined magnitude of force.

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

[0021] In some embodiments, the device further comprises an indicator, the indicator indicating 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 description of the drawings]

[0023] [Figure 1] FIG. 2 is an exploded isometric view of a handle of a system for treating benign prostatic hyperplasia. [Figure 2A] FIG. 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 a cartridge housing assembly of the cartridge of FIG. 2A. [Figure 3A] FIG. 2 is an isometric view of a force limiting assembly according to an embodiment of the present invention. [Figure 3B] FIG. 2 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] 13 is a plan view of a force-limiting assembly according to another embodiment of the present invention; FIG. [Figure 5B] 13 is a plan view of a force-limiting assembly according to another embodiment of the present invention; FIG. [Figure 6] 13 is an isometric view of a force-limiting connector according to another embodiment of the present invention. [Figure 7] FIG. 13 is an isometric view of a handle-cartridge system including a deployment indicator according to another embodiment of the present invention. [Figure 8] FIG. 13 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 PREFERRED EMBODIMENTS

[0024] Numerous specific details are described herein to provide a thorough understanding of the claimed subject matter. However, as will be understood by one of ordinary skill 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 one of ordinary skill in the art have not been described in detail so as not to obscure the claimed subject matter.

[0025] As used herein, the terms "adapted to" or "configured to" are to be considered as 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 to a user, with "proximal" meaning closer relative to the user and "distal" meaning farther relative to the user. The headings, listings, and numbering used herein are for ease of description only and are not meant to limit the invention.

[0026] In general, embodiments of the present disclosure or device of the present invention prevent damage to the therapeutic instrument. The therapeutic instrument delivered to the patient's intervention site may include various tools to treat, remove, or otherwise alter tissue. Such tools include, but are not limited to, needles, cutting blades, vacuum devices, gripping arm assemblies, expandable cutting members, blunt dissectors, nooses or ligation clips, articulating heads with integral or retractable blades, helical blades, radio frequency 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 elongated member of the therapeutic instrument, such that the tool is withdrawn from the elongated member. In some embodiments, the tool may be attached to the distal end of the elongated member, and does not require withdrawal.

[0027] Referring now to the figures, which are provided by way of example and not limitation, embodiments of the present invention relate to an apparatus for limiting and / or attenuating forces applied to moving parts of a therapeutic instrument. Certain embodiments of the present invention additionally or alternatively relate to an apparatus for accommodating relative changes in length between two moving parts of a therapeutic instrument as they move relative to one another. In many cases, embodiments of the present invention can prevent damage to moving parts 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 apparatus 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 tissues, organs, anatomical structures, grafts, or other objects found within a human or animal patient. In certain embodiments, the therapeutic 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, there is shown an exploded isometric view of a BPH treatment instrument handle 100. 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 a number of 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 connected 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 it is squeezed and released by a user. A ratchet 114 connected to a ratchet spring 115 influences the movement of the handle trigger assembly 110 such that the handle trigger assembly 110 does not return to its initial position before it is squeezed a predetermined amount by the user. A safety 112 is connected to the handle trigger assembly 110 to prevent accidental actuation of the handle trigger assembly 110. The handle trigger assembly 110 is connected to a drive gear 113, which is connected to a cam wheel 120.

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

[0031] Specifically, an implant trigger 121 is operatively connected to the cam wheel 120 and an implant sled 160, which is connected to an implant spring 161 that provides the energy associated with delivering or transporting the implant. A needle sled 140 is operatively connected to the cam wheel 120, with a needle sled spring 141 providing the energy associated with delivering the implant. A suture sled 150 is operatively connected to the cam wheel 120, with a suture sled spring 151 providing the energy associated with delivering the implant. In each of these cases, the sleds move 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 serve to attach an endoscope and other ancillary instruments (e.g., surgical sheaths) to facilitate the procedure.

[0033] 2A, which is an isometric view, a cartridge 200 is configured to mate with a treatment instrument handle 100. A cartridge housing assembly 201 fits into the cartridge bay 103 of the treatment instrument handle 100, with the cartridge 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 an exit port for a needle, which is configured to facilitate implant placement. Thus, the treatment instrument handle 100 and cartridge 200 together form a system for placing an implant to treat BPH. A spring and sled in the treatment instrument handle 100 transfer energy and motion to a tab assembly in the cartridge housing assembly 201 to advance the needle into tissue and deploy the implant.

[0034] Region X of Figure 2A is shown in an enlarged isometric view of Figure 2B. The cartridge housing assembly 201 includes a needle tab assembly 240, a suture tab assembly 250, and an implant tab assembly 260. These tab assemblies interact with sleds and springs in the treatment instrument handle to deliver an implant for the treatment of BPH. The linear motion of these tab assemblies translates to mechanical motion at and possibly beyond the distal portion 285 of the cartridge elongate assembly 280. For example, linear motion of the needle tab assembly 240 is associated with movement of the penetrating needle from within the distal portion 285 of the cartridge elongate assembly 280 into tissue, and further linear motion of the needle tab assembly 240 is associated with retraction of the penetrating needle from tissue into the distal portion 285 of the cartridge elongate assembly 280. Similarly, linear motion 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 motion of the suture tab assembly 250 is associated with deployment of the implant into tissue. Additionally, linear motion 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 a 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 each other. As they move together, the needle tab assembly 240 and the suture tab assembly 250 advance the penetrating needle and the implant to a location in the patient's tissue. The implant is coupled to a suture, and the suture is coupled to a suture tube that is 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 each other so that the implant maintains its position in the needle and the implant can be deployed from the needle. The needle and the implant therein advance from a distal portion 285 of the elongated assembly 280 of the cartridge.

[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 with respect 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 accomplished by interaction of the 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 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 for 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 the 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 of the tab assembly with other features of the cartridge and implant may result in certain undesirable results. In certain circumstances, the relative motion of the cartridge and implant features may be compromised, 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 that arise in 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 the spring force transmitted from the suture sled spring through the suture sled to 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 being deployed out of the end of the needle. That is, the friction force partially exceeds the spring force and the implant moves proximally with the retracting needle and therefore never fully exits the end of the needle. In other cases, the end of the needle may become blocked and the implant cannot exit the distal end of the needle.

[0041] One possible consequence of the frictional force being greater than the spring force is damage at or near the proximal end of the suture. For example, the suture and coupled implant move proximally with the retracting needle as described above, but the proximal end of the suture remains fixed by the suture tab assembly. Because the proximal end of the suture is held 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 deploying the implant. That is, if the suture was not damaged, the needle may be retracted, the treatment instrument may be repositioned, and the needle may be deployed again, avoiding non-target tissue causing a deployment failure. 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 may be 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 may be 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 a 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 aspect of the force limiting assembly may be configured to modify a needle tab assembly, an implant tab assembly, or other assembly, where the force limiting aspect is useful for preventing damage to an element being rapidly moved by a spring or other force. In FIGS. 3A and 3B, the 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 is coupled to a force limiting spring 356. As shown in FIG. 4, the suture tab assembly connection block 352 can have a suture tab connection block passage 353. The suture tab connection block passage 353 is present (although hidden) in Figures 3A and 3B, with the suture tube proximal end portion 355 passing through the suture tab connection block passage 353 as one way of coupling the suture tube 351 to the suture tab assembly 350. Although 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 operate 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 operate in certain circumstances may be utilized.

[0043] A force limiting spring 356 is joined to the suture tube proximal end portion 355 and to the suture tab assembly 350. In Figures 3A and 3B, the force limiting spring 356 is shown joined to the suture tab assembly 350 at the suture tab assembly interlocking block passage 352. However, the force limiting spring 356 may be joined to any portion of the suture tab assembly 350, provided that the force limiting spring 356 is configured to perform the force limiting functions disclosed herein. Similarly, the force limiting spring 356 may be joined to the suture tube 351 at any location, provided that the force limiting spring 356 is configured to perform the force limiting functions disclosed herein. Although the 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 tension springs may have hooks or loops, such as, but not limited to, mechanical hooks, crossover center hooks, side hooks, offset saturation hooks, V hooks, extension hooks, rectangular hooks, single or multiple 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. To be clear, the force limiting spring 356 is meant for purposes of illustration to be a mechanism that can accommodate proximal movement of the suture tube and then assist the suture tube in returning 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 increase in frictional force on the distal end of the suture. The increase in frictional force may be due to the needle being bent or buckled, or the distal end of the needle being restrained, such that the implant and connected suture are unable to eject the needle when the needle tab assembly is retracted. That is, forces are transferred from the proximal side to the suture tab assembly 350 further distally on the suture. These transferred forces accommodate the force limiting spring 356 which stretches in a manner to absorb the transferred forces. In this manner, 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 inhibition at the distal portion of the needle.

[0046] Thus, the spring force can be considered as a predetermined force that the frictional force 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, so 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, the suture tube 351 has a friction element 358 near the area where the suture tube 351 is coupled to the suture tab assembly connection block 352. In some embodiments, the friction element 358 is a collar or similar structure that conditionally prevents the suture tube 351 from moving proximally through the suture tab assembly connection block 352 and engaging the force-limiting spring 356. In some embodiments, the friction element 358 is a flattened or crimped section of the suture tube 351 such that the cross-section of the suture tube 351 at the friction element 358 is wider than the remainder of the suture tube 351 in at least one radial direction.

[0048] The conditional nature of the friction element 358 is such that a minimum force is required to push the friction element 358 through the 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 being blocked, must be greater than the force required to push the friction element 358 through the suture tab coupling block passage 353. Thus, there are embodiments in which the restoring force of the 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 slip 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 to either the distal end of the suture tube (e.g., when the needle strikes bone or other hard material) or 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 can also be calibrated based on the location and physical properties of non-target tissue that may be encountered during use of the treatment instrument at the patient's intervention site.

[0050] Some of the embodiments disclosed herein utilize a force limiting spring to help return the suture tube to its initial position. In this case, proper deployment of the implant may be attempted using a reset handle-cartridge system. There are also embodiments in which a mechanism is provided for increasing and / or inhibiting friction at the distal end of the needle, and the suture tube is manually returned to its initial position. In some embodiments, such a system may 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 couples 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 creates a risk of damage to the sutures and / or suture tube. After the latch 458 is disengaged from the notch 459, the implant deployment instrument can be manually moved to a position that resets the suture tab assembly 450 so that the latch 458 re-engages the notch 459. From this reset position, proper deployment of the implant can be attempted.

[0052] In some of the 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 that 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 allow a user to tactilely indicate the presence of a front opening in the left handle case 702 when the needle sled 140 is in the proximal position and the needle of the cartridge is in an undeployed state. 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 needle sled button 745 has completely filled the front opening of the left handle case 702.

[0054] If the needle is not fully deployed from the distal end portion 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 case 702. In this case, the user will be able to tactilely recognize that the needle is incompletely deployed and 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 indicate to the user that the needle is not fully deployed or that the needle is fully deployed. For example, referring back to FIG. 8, a cover plate 830 (similar to cover plate 130 of FIG. 1) is modified to have a mounting post for a hemispherical bell 834. The cover plate 830 further has a feature for mounting a ringer spring 832. The ringer spring 832 protrudes into the interior of the bell 834 (this configuration is space saving compared to a bell striker that is externally attached to the bell). The needle sled 840 is modified to have an alert arm 836 that contacts the ringer spring 832 as the needle sled 840 moves distally during the needle deployment step as described elsewhere herein. The alert arm 836 causes the ringer spring 832 to flex as the alert arm passes under the bell 834. That is, the alert arm 836 folds the ring spring 832 as the alert arm 836 moves distally. The alert arm 836 is configured to release the ring spring 832 when the needle sled 840 moves distally to a position consistent with full needle deployment. The released ring spring 832 pops out and strikes the bell 834, thereby informing 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 the bell 834 from ringing again when the needle sled 840 is redeployed to the initial position and at the end of the deployment sequence, the alert arm 836 has a ramp feature that temporarily moves the ring spring 832 aside instead of folding the bell spring 832. Moving the ringing 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 not affected by the speed of the needle sled. Since the force used to strike the bell is the force produced 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 have aspects that indicate full deployment of the needle and / or incomplete deployment of the needle. There are aspects of the embodiments that prevent damage to the needle or suture assembly and allow manual reset. There are aspects of the embodiments that prevent damage to the needle or suture assembly and aid in resetting the device. Each of these aspects can be used in combination with one another where their use is compatible. For example, there are envisioned embodiments that include a deployment indicator and also include a force limiting feature. Such a force limiting feature can be said to allow manual reset, automatic reset, or both. The separate description of the embodiments does not exclude their combined use.

[0057] Other therapeutic instruments may 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 are actuated, deployed, or driven by mechanical energy) may benefit from the use of the force-limiting springs and connectors disclosed herein, as well as the use of the deployment indicators disclosed herein. Such tools include, but are not limited to, needles, cutting blades, vacuum devices, gripping arm assemblies, expandable cutting members, blunt dissectors, nooses or ligation clips, articulating heads with integral or retractable blades, helical blades, radio frequency 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 instrument having a pusher, sled, or delivery mechanism for moving the tool forward and 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 the 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 a connector that attaches 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 for transferring mechanical energy from the spring mechanism to the cartridge to mate with the cartridge and 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 allow energy to be transferred from the spring mechanism through the first firing sled to fire a 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 to 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 the deployment of the tool 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 hitting bone (or hitting other non-target tissue) can include an adjustable, compressible, expandable, or resettable element coupled to a moveable 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 hitting 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 invention, especially in light of the above teachings.

Claims

1. 1. A device for reducing damage to a medical device, comprising: a treatment tool coupled to a movable assembly at a proximal portion of the treatment tool; a force-limiting element coupled to the proximal portion of the treatment tool and coupled to the movable assembly; a proximal end of the force-limiting element coupled to and in contact with the proximal portion of the treatment tool, and a distal end of the force-limiting element coupled to the movable assembly; The device wherein the proximal end of the force-limiting element remains in contact with the proximal portion of the treatment tool and allows movement of the proximal portion of the treatment tool in a proximal direction relative to the movable assembly, while maintaining the coupling between the movable assembly and the proximal portion of the treatment tool even when the force experienced by the treatment tool increases up to a predetermined force magnitude.

2. The device of claim 1 , wherein the force-limiting element comprises a spring.

3. 3. The apparatus of claim 2, wherein the predetermined magnitude of force is the magnitude of force required to extend the spring.

4. The device of claim 1 , wherein the force-limiting element comprises a reversibly engagable connector.

5. 5. The apparatus of claim 4, wherein the predetermined magnitude of force is the magnitude of force required to disengage the reversibly engagable connector from the movable assembly.

6. The device of claim 1 , wherein the force-limiting element comprises both a spring and a reversibly engagable connector.

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. 10. 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 below a predetermined magnitude of the force.

9. The device of claim 1 , wherein the treatment tool is a suture.

10. The device of claim 1 , wherein the treatment tool is a needle.

11. The device of claim 1 , further comprising an indicator, the indicator indicating when the treatment tool is fully deployed.

12. 12. The device of claim 11, wherein the indicator comprises a visual, auditory, or tactile indicator.

13. 1. A device for reducing the risk of damage to a medical device, comprising: a treatment tool advanceable from the treatment instrument handle; and a restricting element configured to couple a proximal portion of the treatment tool to the treatment instrument handle, wherein the proximal end of the restricting element is coupled to and contacts the proximal portion of the treatment tool and the distal end of the restricting element is coupled to the treatment instrument handle, the proximal end of the restricting element maintaining contact with the proximal portion of the treatment tool and acting to allow proximal movement of the proximal portion of the treatment tool relative to the treatment instrument handle when the distal portion of the treatment tool is subjected to a force above a predetermined magnitude.

14. The device of claim 13 , wherein the restricting element is an adjustable, compressible, extensible, or resettable element.

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

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

17. 14. The device of claim 13, wherein the therapeutic tool is selected from a needle, a cutting blade, a vacuum device, a grasping arm assembly, an expandable cutting member, a blunt dissector, a noose or ligation clip, an articulating head with an integral or retractable blade, a helical blade, a radio frequency energy delivery electrode, a cutting wire or ring, an electrocautery probe, or a staple or suture delivery head.

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

19. 14. The device of claim 13, further comprising an indicator, the indicator indicating when the treatment tool is fully deployed.

20. 20. The device of claim 19, wherein the indicator comprises a visual, auditory, or tactile indicator.

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