Patent Application
20080015575
Various embodiments of the subject instrument are described herein with reference to the drawings wherein:
Referring now to the various figures,
The proximal end 14 of shaft 12 mechanically engages the rotating assembly 80 to facilitate rotation of the electrode assembly 105. In the drawings and in the descriptions which follow, the term “proximal”, as is traditional, will refer to the end of the forceps 10 which is closer to the user, while the term “distal” will refer to the end which is further from the user. Details relating to one envisioned relationship among the various mechanically cooperating components of the shaft 12 and the rotating assembly 80 are described in commonly-owned U.S. patent application Ser. No. 10/460,926 entitled “VESSEL SEALER AND DIVIDER FOR USE WITH SMALL TROCARS AND CANNULAS” the entire contents of which are incorporated by reference herein.
Handle assembly 30 includes a fixed handle 50 and a movable handle 40. Fixed handle 50 is integrally associated with housing 90 and handle 40 is movable relative to fixed handle 50 to actuate the opposing jaw members 110 and 120 of the electrode assembly 105 as explained in more detail below. Movable handle 40 and trigger assembly 70 are of unitary construction and are operatively connected to the housing 90 and the fixed handle 50 during the assembly process. Housing 90 is constructed from two components halves 90a and 90b which are assembled about the proximal end of shaft 12 during assembly. Trigger assembly 70 is configured to selectively provide electrical energy to the electrode assembly 105 for cutting tissue. Switch assembly 60 is disposed proximate to the rotating assembly 80 and is configured to selectively provide electrical energy to the jaw member 110 and 120 to effect a seal. It is envisioned that switch assembly 60 or trigger assembly 70 may be configured to activate both the sealing electrodes and the cutting electrodes during the tissue sealing and division cycle. The generator 551 may be configured to activate the various electrodes according to one or more algorithms. The electrodes may be activated sequentially or simultaneously depending upon a particular purpose.
As mentioned above, electrode assembly 105 is attached to the distal end 16 of shaft 12 and includes the opposing jaw members 110 and 120. Movable handle 40 of handle assembly 30 imparts movement of the jaw members 110 and 120 from an open position wherein the jaw members 110 and 120 are disposed in spaced relation relative to one another, to a clamping or closed position wherein the jaw members 110 and 120 cooperate to grasp tissue therebetween.
Referring now to
Each shaft 212a and 212b includes a handle 217a and 217b disposed at the proximal end 214a and 214b thereof which each define a finger hole 218a and 218b, respectively, therethrough for receiving a finger of the user. As can be appreciated, finger holes 218a and 218b facilitate movement of the shafts 212a and 212b relative to one another which, in turn, pivot the jaw members 210 and 220 from the open position wherein the jaw members 210 and 220 are disposed in spaced relation relative to one another to the clamping or closed position wherein the jaw members 210 and 220 cooperate to grasp tissue therebetween. A ratchet 231 is included for selectively locking the jaw members 210 and 220 relative to one another at various positions during pivoting.
More particularly, the ratchet 231 includes a first mechanical interface 231a associated with shaft 212a and a second mating mechanical interface 231b associated with shaft 212b. Each position associated with the cooperating ratchet interfaces 231a and 231b holds a specific, i.e., constant, strain energy in the shaft members 212a and 212b which, in turn, transmits a specific closing force to the jaw members 210 and 220. It is envisioned that the ratchet 231 may include graduations or other visual markings which enable the user to easily and quickly ascertain and control the amount of closure force desired between the jaw members 210 and 220.
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One of the shafts, e.g., 212b, includes a proximal shaft connector/flange 221 which is designed to connect the forceps 200 to the electrosurgical generator 551. More particularly, flange 221 mechanically secures electrosurgical cable 211 to the forceps 200 such that the user may selectively apply electrosurgical energy as needed.
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It is envisioned that separate electrical connections (e.g., 738) may be utilized to connect the heating elements 724 and 734 to generator 551 or an alternate energy source (not shown). Alternatively, the same electrical connections may be employed to energize both the sealing surfaces 722 and 732 and the heating elements 724 and 734 or the cutting electrodes (See
Referring now to
Knife channel 815 is formed when the jaw members 810 and 820 are closed and the two knife channels 815a and 815b align. Knife channel 815 may be configured as a straight slot with no degree of curvature which, in turn, causes the cutting element 827 to move through the tissue in a substantially straight fashion. Alternatively, the knife channel 815 may be dimensioned to include some degree of curvature to cause the cutting element 827 to move through tissue “t” in a curved fashion. Insulating plate 839 also forms part of the knife channel 815 and includes a channel 815a′ defined therein which extends along insulating plate 839 and which aligns in vertical registration with knife channel half 815a to facilitate translation of cutting element 827 therethrough. A more detailed description of this embodiment is described in commonly-owned U.S. Prov. App. No. 60/722,177 filed Sep. 30, 2005, the entire contents of which is incorporated by reference herein.
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It is envisioned that the electrically conductive heating elements may be activated prior to the application of electrosurgical energy, in conjunction with the application of electrosurgical energy or after the application of electrosurgical energy. Moreover, it is within the scope of the present disclosure for the electrically conductive heating elements to be disposed within one or both of the jaw members and/or within the electrically conductive cutting element.
As can be appreciated, the various geometrical configurations and electrical arrangements of the aforementioned electrode assemblies allow the surgeon to initially activate the two opposing electrically conductive tissue contacting surfaces and seal the tissue and, subsequently, selectively and independently divide tissue either mechanically with a translatable knife or electrically by activating the cutting element and one or more tissue contacting surfaces to cut the tissue utilizing the various above-described and shown electrode assembly configurations. Hence, the tissue is initially sealed and thereafter cut without re-grasping the tissue.
However, it is envisioned that the cutting element may be deployed mechanically without sealing or energized with one or more tissue contacting surfaces to simply cut tissue/vessels without initially sealing. For example, the jaw members may be positioned about tissue and the cutting element may be selectively activated to separate or simply coagulate tissue. This type of alternative embodiment may be particularly useful during certain endoscopic procedures wherein an electrosurgical pencil is typically introduced to coagulate and/or dissect tissue during the operating procedure.
Trigger 70 may be employed to allow the surgeon to selectively activate (energize) one or more tissue contacting surfaces, the pre-heating elements and/or-the cutting element to cut tissue. As can be appreciated, this allows the surgeon to initially seal tissue and then activate the cutting element by simply activating the trigger. Alternatively, the same switch may be employed to initially seal tissue and then cut tissue after a successful seal has been confirmed by the generator algorithm, then the surgeon grasps the tissue and activates one switch to seal and divide tissue.
One or more switches can be placed anywhere on the instrument or may be configured as a remote switch, e.g., handswitch or footswitch. It is also envisioned that the switch may cooperate with a smart sensor (or smart circuit, computer, feedback loop, etc.) which automatically triggers the switch to change between the “pre-heating mode”, the “sealing” mode and the “cutting” mode upon the satisfaction of a particular parameter. For example, the smart sensor may include a feedback loop which indicates when a tissue seal is complete based upon one or more of the following parameters: tissue temperature, tissue impedance at the seal, tissue type, hydration, change in impedance of the tissue over time and/or changes in the power or current applied to the tissue over time. An audible or visual feedback monitor may be employed to convey information to the surgeon regarding the overall seal quality or the completion of an effective tissue seal. A separate lead may be connected between the smart sensor and the generator for visual and/or audible feedback purposes. The smart sensor may be disposed in a variety of different arrangements, including, but not limited to, within or upon the electrically conductive tissue sealing surfaces, cutting elements, or anywhere therebetween.
In one embodiment, the generator 551 delivers energy to the tissue in a pulse-like waveform. Delivering the energy in pulses may increase the amount of sealing energy which can be effectively delivered to the tissue and reduce unwanted tissue effects such as charring. Moreover, the feedback loop of the smart sensor can be configured to automatically measure various tissue parameters during sealing (i.e., tissue temperature, tissue impedance, hydration, heating rate, tissue type, current through the tissue) and automatically adjust the energy intensity and number of pulses as needed to reduce various tissue effects such as charring and thermal spread.
It is also envisioned that electrode assembly 105 (or 205, 305, etc.) may include a sensor capable of detecting temperature changes or changes in the heating rate of the electrode. The sensor may be contained within electrode 105 and could communicate with a feedback control mechanism housed within electrosurgical generator 551 or elsewhere. Various forms of feedback control are well-known and may be utilized in the present disclosure. For a detailed description of modern feedback control systems see FEEDBACK CONTROL OF DYNAMIC SYSTEMS, by G. Franklin et al., Prentice-Hall, Upper Saddle River, N.J., 2002.
It has also been determined that RF pulsing may be used to more effectively cut tissue. For example, an initial pulse from the cutting element through the tissue (or the tissue contacting surfaces through the tissue) may be delivered to provide feedback to the smart sensor for selection of the ideal number of subsequent pulses and subsequent pulse intensity to effectively and consistently cut the amount or type of tissue with minimal effect on the tissue seal. If the energy is not pulsed, the tissue may not initially cut but desiccate since tissue impedance remains high during the initial stages of cutting. By providing the energy in short, high energy pulses, it has been found that the tissue is more likely to cut.
Alternatively, a switch may be configured to activate based upon a desired cutting parameter and/or after an effective seal is created or has been verified. For example, after effectively sealing the tissue, the cutting element may be automatically activated based upon a desired end tissue thickness at the seal.
As mentioned in many of the above embodiments, upon compression of the tissue, the cutting element may act as a stop member and create a gap “G” between the opposing conductive tissue contacting surfaces. Particularly with respect to vessel sealing, the gap distance is in the range of about 0.001 to about 0.006 inches. As mentioned above, controlling both the gap distance “G” and clamping pressure between conductive surfaces are two important mechanical parameters which need to be properly controlled to assure a consistent and effective tissue seal. The surgeon activates the generator to transmit electrosurgical energy to the tissue contacting surfaces and through the tissue to effect a seal. As a result of the unique combination of the clamping pressure, gap distance “G” and electrosurgical energy, the tissue collagen melts into a fused mass with limited demarcation between opposing vessel walls.
Once pre-heated and sealed, the surgeon advances a knife or activates the cutting element to cut the tissue. As mentioned above, the surgeon does not necessarily need to re-grasp the tissue to cut, i.e., the cutting element is already positioned proximate the ideal, center cutting line of the seal. During an electrical cutting phase, highly concentrated electrosurgical energy travels from the cutting element through the tissue to cut the tissue into two distinct halves. As mentioned above, the number of pulses required to effectively cut the tissue and the intensity of the cutting energy may be determined by measuring the seal thickness and/or tissue impedance and/or based upon an initial calibrating energy pulse which measures similar parameters. A smart sensor (not shown) or feedback loop may be employed for this purpose.
As can be appreciated, the forceps may be configured to automatically cut the tissue once sealed or the instrument may be configured to permit the surgeon to selectively divide the tissue once sealed. Moreover, it is envisioned that an audible or visual indicator (not shown) may be triggered by a sensor (not shown) to alert the surgeon when an effective seal has been created. The sensor may, for example, determine if a seal is complete by measuring one of tissue impedance., tissue opaqueness and/or tissue temperature. Commonly-owned U.S. application Ser. No. 10/427,832 which is hereby incorporated by reference herein describes several electrical systems which may be employed to provide positive feedback to the surgeon to determine tissue parameters during and after sealing and to determine the overall effectiveness of the tissue seal.
It is envisioned that heating elements 424 and 434 (or any of the other envisioned heating elements 524, 534, 624, 634, 724, 734, 824, 834, 924 and/or 934 as shown and described herein) may be configured in a variety of different arrangements. For instance, heating elements 424 and 434 may be fixed resistors, variable resistors, varistors, sensitors or thermistors. Elements 424 and 434 may be located in a variety of different areas within electrode assembly 405. Moreover, it is envisioned that the heating elements 424 and 434 may be fixed resistive layers, such as those used during silicon wafer fabrication.
In operation, jaw members 110 and 120 (or 210 and 220, 310 and 320, 410 and 420, etc.) each having a pair of electrically conductive tissue sealing surfaces 422 and 432 (or 522 and 532, etc.) are provided. One jaw member (either 110 or 120, or 210 and 220, etc.) is movable relative to the other from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue “t” therebetween (See
Opposing jaw members (either 110 or 120, or 210 and 220, etc.) are positioned about tissue “t” and electrosurgical energy is applied from electrosurgical generator 551 to the electrically conductive heating elements 424 and 434 (or 524 and 534, etc.) to pre-heat at least one electrically conductive tissue sealing surface 422 and 432. Once sealing surfaces 422 and 432(or 522 and 532, etc.) are pre-heated electrosurgical energy from electrosurgical generator 551 is directed to electrically conductive tissue sealing surfaces 422 and 432 (or 522 and 532, etc.) to cut and/or seal tissue “t”.
The electrosurgical intensity from each of the electrically conductive surfaces, the pre-heating elements and cutting elements may be selectively or automatically controllable to assure consistent and accurate cutting along the centerline of the tissue in view of the inherent variations in tissue type and/or tissue thickness. Moreover, it is contemplated that the entire surgical process may be automatically controlled such that after the tissue is initially grasped the surgeon may simply activate the forceps to seal and subsequently cut tissue. In this instance, the generator may be configured to communicate with one or more sensors (not shown) to provide positive feedback to the generator during the pre-heat, sealing and cutting processes to insure accurate and consistent sealing and division of tissue. Commonly-owned U.S. patent application Ser. No. 10/427,832 discloses a variety of feedback mechanisms which may be employed for this purpose.
From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the present disclosure. For example, it is contemplated that cutting element may be dimensioned as a cutting wire which is selectively activatable by the surgeon to divide the tissue after sealing. More particularly, a wire is mounted within the insulator between the jaw members and is selectively energizable upon activation of the switch.
The forceps may be designed such that it is fully or partially disposable depending upon a particular purpose or to achieve a particular result. For example, the electrode assembly may be selectively and releasably engageable with the distal end of the shaft and/or the proximal end of shaft may be selectively and releasably engageable with the housing and the handle assembly. In either of these two instances, the forceps would be considered “partially disposable” or “reposable”, i.e., a new or different electrode assembly (or electrode assembly and shaft) selectively replaces the old electrode assembly as needed.
It is envisioned that the electrode assembly could be selectively detachable (i.e., reposable) from the shaft depending upon a particular purpose, e.g., it is contemplated that specific forceps could be configured for different tissue types or thicknesses. Moreover, it is envisioned that a reusable forceps could be sold as a kit having different electrodes assemblies for different tissue types. The surgeon simply selects the appropriate electrode assembly for a particular tissue type.
It is also envisioned that the forceps could include a mechanical or electrical lockout mechanism which prevents the pre-heating element(s), sealing surfaces and/or the cutting element(s) from being unintentionally activated when the jaw members are disposed in the open configuration.
Although the subject forceps and electrode assemblies have been described with respect to particular embodiments, it will be readily apparent to those having ordinary skill in the art to which it appertains that changes and modifications may be made thereto without departing from the spirit or scope of the subject devices. For example, although the specification and drawing disclose that the electrically conductive surfaces may be employed to initially seal tissue prior to electrically cutting tissue in one of the many ways described herein, it is also envisioned that the electrically conductive surfaces may be configured and electrically designed to perform any known bipolar or monopolar function such as electrocautery, hemostasis, and/or desiccation utilizing one or both jaw members to treat the tissue. Moreover, the jaw members in their presently described and illustrated formation may be energized to simply cut tissue without initially sealing tissue which may prove beneficial during particular surgical procedures. Moreover, it is contemplated that the various geometries of the jaw members, cutting elements, insulators and semi-conductive materials and the various electrical configurations associated therewith may be utilized for other surgical instrumentation depending upon a particular purpose, e.g., cutting instruments, coagulation instruments, electrosurgical scissors, etc.
It is envisioned that electrosurgical generator 551 may supply energy from a variety of different sources having a range of operating frequencies. Some of these include, but are not limited to, RF energy, microwave, infrared, ultraviolet, X-Ray, and ultrasonic (e.g., an ultrasonic heater capable of providing sonic waves into tissue). Moreover, electrosurgical generator 551 may supply either alternating or direct current and may produce continuous or pulse-like waveforms of varying periodicity, frequency and wavelengths.
It is also envisioned that the geometry of the electrodes may be configured such that the surface area ratios between the electrical poles focus electrical energy at the tissue. Moreover, it is envisioned that the geometrical configurations of the electrodes and insulators may be designed such that they act like electrical sinks or insulators to influence the heat effect within and around the tissue during the sealing or cutting processes.
While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.
