Electrosurgical instrument and system

Abstract

An electrosurgical instrument including an elongated body at least partially covered with an electrically insulative layer from a distal end in a proximal direction and an end effector having opposable arms protruding from said distal end of the elongated body. At least one of the opposable arms is capable of delivering electrical energy to a tissue and the end effector is capable of rotating with respect to the electrically insulative layer when the opposable arms are in an open position.

Description

[0001] ELECTROSURGICAL INSTRUMENT AND SYSTEM

[0002] RELATED APPLICATION / S

[0003] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 681,898 filed on 12 August 2024, the contents of which are incorporated herein by reference in their entirety.

[0004] FIELD AND BACKGROUND OF THE INVENTION

[0005] The present invention relates to an electrosurgical instrument and to a system incorporating same. Embodiments of the present invention relate to an electrosurgical forceps that is fully insulated to the tip and is capable of end effector rotation with respect to the shaft as well as shaft deflection.

[0006] Electrosurgery is used routinely in both open and laparoscopic procedures to cut, coagulate, dissect, fulgurate, ablate and shrink tissue. High frequency alternating electric current at various voltages is provided from a generator to a handpiece having one or more electrodes positioned on an end effector (e.g., jaws). The energy is passed by the electrode(s) to the tissue to generate heat.

[0007] Various mono-polar and bi-polar jaw structures have been developed for delivering the electrical energy to the tissue. In a typical arrangement of a bi-polar jaws, one of the jaws functions as active electrode and the second as a return electrode thus only the tissue that is grasped is included in the electrical circuit. In monopolar jaw arrangements, both jaws function as an active electrode that carries an HF current to tissue while the return electrode is connected to Patient.

[0008] Although electrosurgery provides many benefits, there are potential risks including unintended patient burns, shock to the surgeon and potential fires in the operating room.

[0009] During an electro surgery procedure the surgeon has a limited view of the working space. In addition, reaching the target tissue oftentimes requires maneuvering of the end effector. Due to the confined space, lack of vision and maneuvering required, application of an electrical current, especially if the end effector is not well insulated, can result in an unintended electrical discharge that can burn an organ or tissue.

[0010] While reducing the present invention to practice, the present inventors have devised an electrosurgical device that is tightly insulated and yet highly maneuverable thereby minimizing the aforementioned problems encountered during electrosurgery. SUMMARY OF THE INVENTION

[0011] According to one aspect of the present invention there is provided an electrosurgical instrument comprising an elongated body at least partially covered with an electrically insulative layer from a distal end in a proximal direction and an end effector having opposable arms protruding from the distal end of the elongated body, wherein at least one of the opposable arms is capable of delivering electrical energy to a tissue and further wherein the end effector is capable of rotating with respect to the electrically insulative layer when the opposable arms are in an open position.

[0012] According to embodiments of the present invention the opposable arms open and close around a pivot point positioned within a region of the elongated body covered by the electrically insulative layer.

[0013] According to embodiments of the present invention the opposable arms are actuated to open and close via a drive mechanism positioned proximally to the pivot point.

[0014] According to embodiments of the present invention the drive mechanism includes a movable piston having a pair of slots for engaging a pair of pins in proximal portions of the oppo sable arms.

[0015] According to embodiments of the present invention the instrument further comprises a cable attached to the piston.

[0016] According to embodiments of the present invention the instrument further comprises a handle attached to a proximal end of the shaft, the handle including an actuator for pulling and pushing the cable.

[0017] According to embodiments of the present invention at least a portion of the elongated body is steerable.

[0018] According to embodiments of the present invention the instrument further comprises a tube forming a distal portion of the elongated body.

[0019] According to embodiments of the present invention the instrument further comprises a bearing attached to a proximal end of the tube.

[0020] According to embodiments of the present invention the movable piston translates longitudinally within a slot of a slotted tube covered by the electrically insulative layer.

[0021] According to embodiments of the present invention the movable piston includes a protrusion to prevent non-longitudinal movement within the slotted tube.

[0022] According to embodiments of the present invention the proximal portions do not protrude out of the elongated body when the opposable arms are open. According to embodiments of the present invention the slotted tube is covered by a lubricant.

[0023] According to embodiments of the present invention the opposable arms are shaped as grasper jaws.

[0024] According to embodiments of the present invention the opposable arms are shaped as cutting blades.

[0025] According to another aspect of the present invention there is provided an electrosurgical system comprising the instrument described herein and an RF generator.

[0026] According to embodiments of the present invention the system is configured for bipolar electro surgery.

[0027] According to embodiments of the present invention the system is configured monopolar electro surgery.

[0028] According to another aspect of the present invention there is provided a method of treating tissue comprising positioning an electrosurgical device having opposable arms near the tissue, the electrosurgical device being at least partially covered with an electrically insulative layer from a distal end in a proximal direction; rotating the opposable arms of the electrosurgical device while in an open position to align with the tissue while the insulative layer remains stationary; and grasping the tissue and delivering electrical energy thereto thereby treating the tissue.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0030] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0031] The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

[0032] In the drawings:

[0033] FIG. 1 illustrates an electrosurgical instrument constructed in accordance with the teachings of the present invention.

[0034] FIG. 2 illustrates the distal portion of the present instrument showing a portion of the elongated body and the end effector configured with oppo sable jaws.

[0035] FIG. 3 illustrates the internal components of the distal portion of the present instrument.

[0036] FIGs. 4, 5 and 6 illustrate the pushrod, piston and slotted tube components of the drive mechanism of the present instrument.

[0037] FIG. 7 illustrates the piston and rod components of the drive mechanism of the present instrument.

[0038] FIG. 8A-B illustrate configurations of the present instrument having a tube covering the drive mechanism.

[0039] FIG. 9 illustrates an end effector configuration having opposable arms shaped as blades.

[0040] FIG. 10 illustrates an electrosurgical system including the present instrument connected to an RF generator.

[0041] FIGs. 11 and 12 are images of a prototype scissor (Figure 11) and dissector (Figure 12).

[0042] DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

[0043] The present invention is of an electrosurgical instrument which can be used in open or laparoscopic electrosurgery. Specifically, the present invention can be used to cut, coagulate, dissect, fulgurate, ablate and shrink tissue while minimizing the risk of electrical arcing

[0044] The principles and operation of the present invention may be better understood with reference to the drawings and accompanying descriptions.

[0045] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details set forth in the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0046] Electrosurgical instruments are well-known in the art and typically include a shaft attached to an end effector. In order to prevent unintentional arcing from exposed conductive surfaces, the shaft of such instruments is completely insulated up to the end effector jaws. End effector rotation is achieved by rotating the entire shaft or a distal portion thereof. In configurations enabling the latter functionality, a gap in the insulative layer enables end effector rotation but can be a source of arcing.

[0047] To traverse this limitation of instruments having insulation layer gaps while providing end effector rotation with respect to the shaft of the instrument, the present inventors devised an electrosurgical instrument that includes a contiguous insulative cover from the instrument tip proximally and an end effector configuration that enables rotation of the end effector arms (e.g., jaws, blades) with respect to the insulative cover.

[0048] Thus, according to one aspect of the present invention there is provided an electrosurgical instrument. The electrosurgical instrument of the present invention can be used along with any RF generator in an electrosurgical system that can be used to cut, coagulate, dissect, fulgurate, ablate and shrink tissue using high frequency alternating electric current at various voltages and a monopolar or bipolar setup.

[0049] A typical setup for electrosurgery includes an electrosurgical unit (ESU), an active accessory (e.g. a monopolar / bipolar instrument), a footpedal, an extension cable and a return pad (in the case of monopolar instruments). Common ESUs include Valleylab, Megadyne and Vio. Typical power settings range from 10-70W depending on the tissue involved and the operation mode (e.g. cut, coag, blend). Typical maximal voltage ratings for active accessories are 3000Vp rating for monopolar and 600 Vp rating for bipolar.

[0050] The present electrosurgical instrument (also referred to herein as “instrument”) includes an elongated body (e.g., shaft) at least partially covered with an electrically insulative layer from a distal end in a proximal direction. The insulative layer can be contiguous and does not include gaps. The elongated body can be fabricated from stainless steel (e.g., AISI 304) and can be 330 cm in length and 5 mm in outer diameter. The insulative layer can be made from Polyolefin and can be 0.1-0.2 mm thick. The insulative layer preferably covers the entire length of the elongated body.

[0051] At least a portion of the elongated body can be configured for deflection (steering) by fabricating this portion from a flexible tube, a tube with cutouts or interlocking segments. The steerable portion can be deflected using pull wires running within a lumen of the elongated body or through dedicated channels within the wall of the elongated body. One example of a steerable shaft is described in US20200113557A1 which is incorporated herein by reference.

[0052] The instrument further includes an end effector having opposable arms (shaped as, for example, grasping jaws or cutting blades) protruding from the distal end of the elongated body. The arms include a proximal portion that can reside outside or within the elongated body. The arms can be 10-25 mm in length and 1-5 mm in width and can be arced or oval -shaped. The internal surface of the arms (grasping or cutting surface) can have serrations or teeth or it can be smooth.

[0053] At least one of the opposable arms is configured capable of delivering electrical energy to a tissue, in the case of a monopolar setup (system), both arms act as a positive pole, while the whole arm is a conductive part, in the case of a bipolar setup, one arm is the positive pole, and another is the negative pole.

[0054] As is described in detail hereinbelow with reference to the Figures, the instrument is configured such that the end effector is capable of rotating with respect to the electrically insulative layer when the opposable arms are in an open position (and when closed).

[0055] The instrument can further include a handle attached to a proximal end of the elongated body. The handle can include mechanisms for delivering electrical energy to the electrode(s) of the end effector, for deflecting the steerable portion and for opening / closing and rotating the arms.

[0056] The instrument can include a drive mechanism for opening / closing and optionally rotating the opposable arms.

[0057] In order to enable the end effector to rotate with respect to the insulative layer, the proximal portion of the end effector (residing within the elongated body) is configured such that when the opposable arms are open, the proximal portion of the opposable arms do not extend radially outward beyond the diameter of the elongated body.

[0058] On example of such a mechanism is disclosed in US5,749,881 the teachings of which is incorporated herein by reference.

[0059] Alternatively, the drive mechanism can include, for example, a movable piston having a pair of slots for engaging a pair of pins in proximal portions of the opposable arms. This configuration of the drive mechanism is further described hereinbelow with reference to the Figures.

[0060] The electrosurgical instrument of the present invention can be used along with any RF generator in an electrosurgical system

[0061] Referring now to the drawings, Figures 1-10 illustrate the present instrument (Figures 1- 9) which is referred to herein as instrument 10 and an electrosurgical system (Figure 10) which is referred to herein as system 100.

[0062] As is shown in Figure 1, instrument 10 includes an elongated body 12 (shaft) shaped generally as a tube. Opposable arms 14 of end effector 16 protrude from distal end 18 of elongated body 12 (Figure 2). Proximal portions 20 of opposable arms 14 (Figure 3) can reside within elongated body 12 as is shown in Figures 2 and 3.

[0063] Elongated body 12 can be covered with an insulative layer 22 from distal end 18 proximally, insulative layer 22 can cover the entire length of elongated body or a portion thereof.

[0064] Elongated body 12 can include a steerable portion 13 (Figure 3) that is deflected using wires actuated from handle 32 (described below). Steerable portion 13 is fabricated from Grilamid (e.g., US20200113557A1) and includes an internal lumen through which a push / pull rod 46 is positioned (further describe below).

[0065] Opposable arms 14 can be shaped as jaws as is shown, for example, in Figures 2 and 3 or as blades (Figure 9). One or more electrodes 24 can be positioned on an inner surface 26 of opposable arms 14 (Figure 3). Electrode(s) 24 can form a part of inner surface 26 or be attached thereto and are made from conductive material.

[0066] Opposable arms 14 of end effector 16 can be connected via pin 30 to form a hinge around which arms 14 rotate (in a scissor-like movement). Pin 30 as well as proximal portions 20 of opposable arms 14 can reside within elongated body 12 and thus are covered by insulative layer 22.

[0067] Instrument 10 further includes a handle 32 attached to a proximal end 34 of elongated body 12. Handle 32 includes mechanisms for rotating and actuating (open / close) end effector 16, steering a portion of elongated body 12 and for optionally delivering electrical energy to electrode(s) 24. In the example shown in Figure 1, handle 32 includes a palm interface 33 that is mounted on a gimble 35 and can be tilted side to side and forward back. Handle 32 can also include a fingers interface 37 that can be opened and closed and rotated. Palm interface 33 can be used to deflect a steerable portion of elongated body 12 (in one or more directions, e.g., 2, 3, 4 etc.) while fingers interface 37 can be used to open and close and rotate the end effector. Handle 32 can also include a drive unit 39 that includes a motor for deflecting the steerable portion and actuating the end effector.

[0068] Figures 3-8B illustrate drive mechanism 40 of end effector 16 in greater detail. Drive mechanism 40 includes piston 42 that slides within slotted tube 44 and is connected to a push / pull element 46 (wire / tube / rod) actuated from handle 32. Push / pull rod 46 opens and closes end effector 16 as well as rotates it with respect to elongated body 12 (and insulative layer 22).

[0069] Piston 42 includes a pair of slots 48 for engaging a pair of pins 50 in proximal portions 20 of opposable arms 14 (Figure 3). Slots 48 are formed in both sides of piston 42 and are diagonal and opposing, i.e., on one side slot 48 runs lengthwise and diagonally from bottom to top and on the other side from tope to bottom.

[0070] As piston 42 translates backwards longitudinally within slotted tube 44 pins 50 of proximal portions 20 slide forward within slots 48 with a first pin 50 sliding up and forward and a second pin 50 sliding down and forward. Such movement scissors opposable arms open (Figures 5 and 6).

[0071] In order to enable rotation of end effector 16 and drive mechanism 40 within elongated body and with respect to insulative layer 22, a bearing 52 that is connected, at an outer circumference, to elongated body 12 / insulative layer 22 and to slotted tube 44 at an inner circumference.

[0072] In cases where insulative layer 22 directly covers slotted tube 44, the interface therebetween can be optionally covered with a lubricant to allow slotted tube to easily rotate against the inner surface of insulative layer 22. With such a configuration, piston 42 can include a protrusion 43 (Figures 4 and 7) to prevent non-longitudinal movement of piston 42 within slotted tube 44 (i.e., to prevent piston 42 from ‘jumping out’ of the slot of slotted tube 44 and impinging on insulative layer 22. In such cases, proximal portions 20 of opposable arms 14 may protrude from the elongated body 12, slightly stretching insulative layer 22.

[0073] Alternatively, a tube 60 (Figure 8A) that is attached to bearing 52 can be used as a cover for slotted tube 44 in order to prevent such unwanted movement of piston 42. In such a configuration slotted tube rotates within tube 60 and lubrication is thus not necessary.

[0074] In another configuration (Figure 8B), slotted tube 44 frictionally rotates within tube 60 (without end bearing), which is covered by an insulation or protective layer 22 (in a case where the end effector is a grasper or scissor). Tube 60 remains fixed relative to shaft 12, allowing a single insulation / protective layer to effectively cover both the shaft and the rotating mechanism of the end-effector without inducing torsion stress on the insulative / protective layer. The endeffector’s open-close mechanism is designed such that the proximal protrusions of the jaws stop against the sleeve. Additionally, tube 60 includes a geometric feature that creates a stop for slotted tube 44, preventing axial movement. This design minimizes the projected length of the instrument, enabling surgeons to operate efficiently in smaller areas.

[0075] Figure 10 illustrates system 100 that includes instrument 10 and an RF generator 102 (ESU) connected thereto via power link 104. System 100 can additionally include a foot pedal, an extension cable and a return pad (in the case of a monopolar instrument). Typical power settings range from 10-70W with coagulation as the most common mode of operation. In a typical surgical procedure, the surgeon contacts / grasps the target tissue with instrument 10 and presses the foot pedal to activate the electrosurgical energy to cut, coagulate, dissect, fulgurate, ablate or shrink the tissue. The surgeon can then rotate the head of instrument 10 and / or steer the steerable portion of the shaft to better position the jaws / blades while maintaining the insulative layer stationary against non-target tissue and repeat the application of energy to the tissue.

[0076] As used herein the term “about” refers to ± 10 %.

[0077] Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting.

[0078] EXAMPLES

[0079] Reference is now made to the following examples, which together with the above descriptions, illustrate the invention in a non limiting fashion.

[0080] A usability study was conducted on an early prototype with insulation not extending over the proximal portion of the end effector. Feedback from the study indicated that one concern with such a design was the possibility of creating thermal damage to the tissue in an unintended area due to arcing.

[0081] The feedback led to a design improvement that extended the insulation layer to cover the proximal portion of the end effector and reduce the abovementioned risk.

[0082] Prototypes of a scissor (Figure 11) and dissector (Figure 12) were tested ex-vivo for performance and usability on isolated porcine tissues.

[0083] With both instruments the energy activation was excellent with the energy passing through the target tissue without arcing. Safety was excellent and the surgeons noted that the fact that the end effector was covered by the insulation layer significantly increases their confidence in using these instruments.

[0084] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

[0085] It is the intent of the applicant(s) that all publications, patents and patent applications referred to in this specification are to be incorporated in their entirety by reference into the specification, as if each individual publication, patent or patent application was specifically and individually noted when referenced that it is to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is / are hereby incorporated herein by reference in its / their entirety.

Claims

WHAT IS CLAIMED IS:

1. An electrosurgical instrument comprising an elongated body at least partially covered with an electrically insulative layer from a distal end in a proximal direction and an end effector having opposable arms protruding from said distal end of the elongated body, wherein at least one of said opposable arms is capable of delivering electrical energy to a tissue and further wherein said end effector is capable of rotating with respect to the electrically insulative layer when said opposable arms are in an open position.

2. The instrument of claim 1, wherein the opposable arms open and close around a pivot point positioned within a region of the elongated body covered by the electrically insulative layer.

3. The instrument of claim 2, wherein said opposable arms are actuated to open and close via a drive mechanism positioned proximally to said pivot point.

4. The instrument of claim 3, wherein said drive mechanism includes a movable piston having a pair of slots for engaging a pair of pins in proximal portions of said opposable arms.

5. The instrument of claim 4, further comprising a cable attached to said piston.

6. The instrument of claim 5, further comprising a handle attached to a proximal end of said shaft, said handle including an actuator for pulling and pushing said cable.

7. The instrument of claim 1, wherein at least a portion of said elongated body is steerable.

8. The instrument of claim 4, further comprising a tube forming a distal portion of said elongated body.

9. The instrument of claim 8, further comprising a bearing attached to a proximal end of said tube.

10. The instrument of claim 4, wherein said movable piston translates longitudinally within a slot of a slotted tube covered by said electrically insulative layer.

11. The instrument of claim 10, wherein said movable piston includes a protrusion to prevent non-longitudinal movement within said slotted tube.

12. The instrument of claim 4, wherein said proximal portions do not protrude out of said elongated body when said opposable arms are open.

13. The instrument of claim 10, wherein said slotted tube is covered by a lubricant.

14. The instrument of claim 1, wherein said opposable arms are shaped as grasper jaws.

15. The instrument of claim 1, wherein said opposable arms are shaped as cutting blades.

16. An electrosurgical system comprising the instrument of claim 1 and an RF generator.

17. The system of claim 16, configured for bipolar electrosurgery.

18. The system of claim 16, configured for monopolar electrosurgery.

19. A method of treating tissue comprising:(a) positioning an electrosurgical device having opposable arms near the tissue, said electrosurgical device being at least partially covered with an electrically insulative layer from a distal end in a proximal direction;(b) rotating said opposable arms of said electrosurgical device while in an open position to align with the tissue while said insulative layer remains stationary; and(c) grasping the tissue and delivering electrical energy thereto thereby treating the tissue.

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