Patent Application
20120289958
This invention relates generally to the field of minimally invasive surgery, and in particular to a hand-held, bipolar laparoscopic device for electrical or mechanical cutting of biological tissue and for coagulation of the tissue.
Nearly every open and laparoscopic surgical procedure requires the cutting and sealing of vascularized tissue. To reduce or minimize bleeding of the tissue, conventional surgical scissors have begun to be replaced with electrically energized scissors in monopolar and bipolar configurations, each offering certain advantages and disadvantages. Monopolar refers to a configuration where a return electrode is coupled to a patient, typically in the form of a patch coupled to the patient's skin, so that only one active electrode need be carried on the surgical instrument. With the monopolar technique, a concentrated electrical current is delivered from the active electrode on the instrument to targeted tissue, causing coagulation that stops bleeding. The electricity then disperses and flows through the patient en route to the return electrode attached to the patient's skin. Bipolar refers to a configuration wherein the instrument carries both the active and return electrodes, delivering energy to tissue between the two electrodes.
Monopolar electrosurgical instruments facilitate several surgical functions, such as cutting tissue, coagulating tissue to stop bleeding, or concurrently cutting and coagulating tissue. The surgeon can apply a current whenever the conductive portion of the instrument is in electrical contact with the patient, permitting the surgeon to operate with monopolar instruments from many different angles. However, as stated above, monopolar electrosurgical instruments do have some drawbacks, especially when used for laparoscopic procedures.
During laparoscopic monopolar electrosurgery, the view of the surgical field is somewhat constricted. The surgeon operates from the exterior of the patient's body using remote instrumentation. The manipulation of instruments and tissue is based on magnified images that are relayed from a camera connected to a laparoscope and displayed on a monitor. The active electrode may be in close proximity to other conductive instruments and to tissue, and may result in stray electrical current being transmitted to unseen tissue off the extended shaft of the remote laparoscopic instruments, possibly leading to thermal injury to the patient.
Stray currents may cause patient injury outside the laparoscope's view via direct coupling, insulation failure, or capacitive coupling. Direct coupling occurs when the active electrode touches another metal instrument within the patient, such as in the abdomen, transferring energy to the second instrument and possibly injuring tissue with which it comes in contact.
Insulation failure occurs when the insulated shaft of the electrode, which is designed to protect against the release of stray electrical current, becomes compromised due to insulation breakdown. The breakdown along the unseen shaft of an activated electrode can allow electrical current to leak into surrounding non-targeted tissue, causing unobserved damage.
Capacitive coupling occurs when electrical current is induced from the active electrode to nearby conductive material, despite intact insulation. During electrosurgery, the charge on the active electrode switches from highly positive to highly negative at a very high frequency. The rapidly varying electrical field around the active electrode is only partially impeded by electrical insulation and creates stray electrical currents by alternately attracting and repelling ions in surrounding body tissue. The movement of electrically charged ions in capacitively coupled tissue can cause currents that can heat tissue sufficiently to produce a burn.
In comparison to monopolar surgical instruments, such as monopolar scissors, the electrical current in a bipolar arrangement is not required to travel long distances through the patient before returning to the return electrode, thereby greatly reducing the minute risk of accidental burns. Instead, a bipolar electrode arrangement applies electrical current only between two energized cutting blades which are closely spaced and always within the field of view of the surgeon. A bipolar arrangement also requires less electrical power than a monopolar arrangement because the electrical current disperses through a much smaller volume of tissue. More importantly, a bipolar arrangement eliminates the possibility of accidental burns through an insulation failure of the active shaft and greatly reduces the risk of direct coupling and capacitive coupling. However, bipolar instruments require the surgeon to carefully position the instrument to ensure that both the active and return electrodes are in electrical contact with the patient before applying a current. This may limit the range of motion and the angle from which the surgeon can effectively use the bipolar instrument.
There are several variations for placement of electrodes on electrosurgical scissors that allow electrical current to flow through the cut tissue. For example, the exterior surface of one shearing member can include an active electrode while the exterior surface of the other shearing member can include a return electrode. In this configuration, electrosurgical current can flow from the exterior surface of one blade, through the cut tissue, to the exterior surface of the other blade.
In another variation, each of the two shearing surfaces includes an active electrode, while each of the two exterior surfaces includes a return electrode, or vice versa. In this configuration, electrical current can flow from each shearing surface, through the cut tissue, to an exterior surface, or vice versa.
Apart from mechanical cutting, the practicality of monopolar scissors makes them more favorable to surgeons. Monopolar scissors not only permit a surgeon to coagulate tissue between the blades prior to cutting the tissue mechanically, but they also permit the surgeon to dissect thin connective tissue electrically by moving one blade in a sweep-like motion over the tissue. Monopolar scissors also permit electrosurgical coagulation of small blood vessels that are cut open during a mechanical cutting process. This is typically performed by energizing the tissue with the exterior surface of one of the scissor blades.
Conventional bipolar scissors also permit electrical coagulation and cutting of the tissue between the blades, but they do not allow for the common practice to utilize one blade for dissection of tissue by moving the blade in a sweep-like motion over the tissue. Conventional bipolar scissors also do not allow for simultaneous coagulation of tissue between the blades and surrounding tissue, or coagulating the tissue by energizing it with the exterior surface of one of the blades. This is due to the common approach to separate the high frequency (HF) coagulation and mechanical cutting action both spatially and functionally by arranging the active, electrically conductive, radio frequency (RF) electrodes on the outside of each electrically conductive blade, while being electrically insulated through insulators, such as ceramic or plastic.
One improved bipolar scissors includes blades having electrodes on the inner surface of each blade with the electrodes being connected to the same pole to avoid a short circuit between the mating inner faces of the blades. The outer surface of each of the blades includes at least two electrodes connected to opposite poles, meaning that at least one of the electrodes on the outer surface of each blade is connected to the same pole as the electrode on the inner surface of the blade. With these scissors, all of the electrodes are energized simultaneously and there are no means to have less than all of the electrodes energized when applying electrical current to the electrodes. In this manner, it is not possible to coagulate only the tissue between the blades. If an electrical current is applied while cutting the tissue, the surrounding tissue is also coagulated.
The deficiencies of the prior art are overcome with the present invention, which includes a bipolar electrosurgical scissors for use in treating biological tissue. The bipolar electrosurgical scissors includes a first and second scissor blade. Each of the first and second scissor blades has a shearing surface, an opposed surface that is opposite the shearing surface, a cutting edge, a first, proximal end, and a second, distal end. The shearing surface and cutting edge of each of the scissor blades is electrically neutral. The shearing surface of the first blade and the shearing surface of the second blade face each other and interface with each other. A pivot pin pivotally couples the first scissor blade to the second scissor blade at a position that is proximal to the shearing surfaces of the first and second scissor blades. The bipolar electrosurgical scissors also include a first electrical connection for receiving an electrical current of a first polarity and a second electrical connection for receiving an electrical current of a second polarity, which is opposite to the first polarity. Each of the first and second scissor blades includes at least one exposed first electrode and at least one exposed second electrode positioned on the opposed surface of the respective scissor blade and extending lengthwise along the length of the respective scissor blade. The at least one first electrode on the first scissor blade is coupled to the first electrical connection. The at least one second electrode on the first scissor blade is coupled to the second electrical connection. The at least one first electrode on the second scissor blade is coupled to the second electrical connection. The at least one second electrode on the second scissor blade is coupled to the first electrical connection. In a first energized state, the first electrical connection delivers electrical current only to the at least one first electrode on the first scissor blade and the second electrical connection delivers electrical current only to the at least one first electrode on the second scissor blade. In a second energized state, the first electrical connection delivers electrical current to the at least one first electrode on the first scissor blade and to the at least one second electrode on the second scissor blade. In the second energized state, the second electrical connection delivers electrical current to the at least one second electrode on the first scissor blade and to the at least one first electrode on the second scissor blade.
In another aspect, the distance between the at least one first electrode and the at least one second electrode on the opposed surface of each of the first and second scissor blades is sufficient to prevent electrical arcing between the electrodes, and small enough to permit simultaneous connection between the tissue and two respective electrodes having opposing polarity.
In another aspect, each of the first and second scissor blades includes a laminated structure having a first layer, a second layer, a third layer, a fourth layer and a fifth layer. The first layer on each of the first and second scissor blades coincides with the shearing surface and cutting edge of the respective scissor blade and includes a first, shearing surface and a second, opposed surface. The first surface of the first layer forms the shearing surface of the respective blade. The second layer is coupled to the second surface of the first layer. The second layer is electrically nonconductive and includes a material that insulates against electrical current. The third layer is coupled to the second layer on the side opposite the first layer. The third layer is electrically conductive and exposed portions of the third layer form the at least one first electrode of the respective scissor blade. The fourth layer is coupled to the third layer on the side opposite the second layer. The fourth layer is electrically nonconductive and includes a material that insulates against electrical current. The fifth layer is coupled to the fourth layer on the side opposite the third layer. The fifth layer is electrically conductive and exposed portions of the fifth layer form the at least one second electrode of the respective scissor blade. In another facet, the second layer of each of the first and second scissor blades completely separates the third layer from the first layer and provides insulation between the third layer and the first layer of the respective scissor blade. Likewise, the fourth layer of each of the first and second scissor blades completely separates the third layer from the fifth layer and provides insulation between the third layer and the fifth layer of the respective scissor blade. In another facet, the electrically insulating material of the second and fourth layers of the first and second scissor blades has sufficient dielectric strength to substantially prevent electrical breakdown of the electrically insulating material. In another facet, the exposed surfaces of the third layer of each of the first and second scissor blades forms at least two first electrodes and the exposed surfaces of the fifth layer of each of the first and second scissor blades form at least one second electrode. In another facet, the exposed surfaces of the fifth layer of each of the first and second scissor blades forms one second electrode positioned between the at least two first electrodes of the respective scissor blade.
In another aspect, the first layer of each of the first and second scissor blades includes a first edge surface, which coincides with the cutting edge, and a second edge surface. In another facet, the scissors include an electrically insulating coating on the first layer of each of the first and second scissor blades. The electrically insulating coating covers the shearing surface, the cutting edge, the portion of the first edge surface proximate the shearing surface and the portion of the second edge surface proximate the shearing surface. The first layer of each of the blades includes at least one first electrode positioned on each of the first and second edge surfaces at the portions of the first and second edge surfaces that are proximate the opposed surface of the respective first layer. The portions of the first and second edge surfaces of the first layers on the first and second scissor blades that form the first electrodes on the first layers are not covered with the electrically insulating coating. In another facet, the electrically insulating coating on the shearing surfaces of the first and second scissor blades includes an amorphous diamond-like carbon. In another facet, the exposed surfaces of the third layers of each of the first and second scissor blades form at least two second electrodes of the respective blade. The exposed surfaces of the fifth layer of each of the first and second scissor blades form at least one first electrode of the respective blade. In another facet, in the first energized state, the first electrical connection delivers electrical current only to the first electrodes positioned on the first layer of the first scissor blade and the second electrical connection delivers electrical current only to the first electrodes positioned on the first layer of the second scissor blade. In another facet, the distance between the first electrodes on the first and second edge surfaces of adjacent first layers of the first and second scissor blades, with the scissors in a closed condition, is sufficient to prevent electrical arcing between the electrodes. The distance between the first electrodes on the first and second edge surfaces of adjacent first layers of the first and second scissor blades, with the scissors in a closed condition, is small enough to permit simultaneous connection between the tissue and a first electrode on the first scissor blade and a first electrode on the second scissor blade.
In another aspect, each of the first and second scissor blades of the bipolar electrosurgical scissors includes an insulating body having a primary surface that corresponds with the shearing surface of the blade and a secondary surface that corresponds with the opposed surface of the blade. Each of the first and second scissor blades also includes a shearing layer that has a first, shearing surface, a second, opposed surface, and the cutting edge. The opposed surface of the shearing layer is coupled to the primary surface of the insulating body. The at least one first electrode and the at least one second electrode are coupled to, inlayed into, or deposited onto the secondary surface of the insulating body of each of the first and second scissor blades. The first and second electrodes are positioned in an alternating relationship with the first and second electrodes on the second scissor blade corresponding with the first and second electrodes on the first scissor blade. In another facet, the distance between the at least one first electrode and the at least one second electrode on the opposed surface of each of the first and second scissor blades is sufficient to prevent electrical arcing between the electrodes in an open configuration, and small enough to permit simultaneous connection between the tissue and two respective electrodes having opposing polarity. In another facet, the material that forms the electrically insulating body of each of the first and second scissor blades has sufficient dielectric strength to substantially prevent electrical breakdown of the electrically insulating body.
In another aspect, the shearing layer of each of the first and second scissor blades includes a first edge surface and a second edge surface. The first edge surface coincides with the cutting edge of the respective blades. In another facet, the scissors include an electrically insulating coating on the shearing layer of the first and second scissor blades. The electrically insulating coating covers the shearing surface, the cutting edge, the portion of the first edge surface proximate the shearing surface and the portion of the second edge surface proximate the shearing surface. The scissors also include at least one first electrode positioned on each of the first and second edge surfaces of the shearing layer of each of the first and second scissor blades at the portion of the respective edge surface that is proximate the opposed surface of the respective shearing layer. In another facet, the electrically insulating coating on the shearing surfaces of the first and second scissor blades includes an amorphous diamond-like carbon. In another facet, in the first energized state, the first electrical connection delivers electrical current only to the first electrodes positioned on the shearing layer of the first scissor blade and the second electrical connection delivers electrical current only to the first electrodes positioned on the shearing layer of the second scissor blade. In another facet, the distance between the first electrodes on the first and second edge surfaces of adjacent shearing layers of the first and second scissor blades, with the scissors in a closed condition, is sufficient to prevent electrical arcing between the electrodes. The distance between the first electrodes on the first and second edge surfaces of adjacent shearing layers of the first and second scissor blades, with the scissors in a closed condition, is small enough to permit simultaneous connection between the tissue and a first electrode on the first scissor blade and a first electrode on the second scissor blade.
These and other features and advantages of the invention will be clarified with a description of the embodiments and reference to the associated drawings.
The invention and its various embodiments can now be better understood with the following detailed description wherein illustrated embodiments are described. It is to be expressly understood that the illustrated embodiments are set forth as examples and not by way of limitations on the invention.
Referring to
With continuing reference to
Referring to
With continuing reference to
Referring to
The first layer 48 coincides with the shearing surface 28 and cutting edge 32 of the scissor blades 24, 26. The first layer 48 includes a first, shearing surface 49 and a second, opposed surface 51, and is made of a material capable of forming a desirable cutting edge, such as a metal or other materials that are well known in the art. As stated above, the shearing surface 28 of each of the first and second blades 24, 26 is electrically neutral. Thus, the first layer 48 is not coupled to either of the first or second electrical connections 40, 42. The second layer 50 is coupled to the second surface 51 of the first layer 48. The third layer 52 is coupled to the second layer 50 on the side opposite the first layer 48. The third layer 52 is electrically conductive. The fourth layer 54 is coupled to the third layer 52 on the side opposite the second layer 50. The fifth layer 56 is coupled to the fourth layer 54 on the side opposite the third layer 52. The fifth layer 56 is electrically conductive.
With continuing reference to
The fifth layer 56 includes exposed portions 60 that form the at least one second electrode 46 on each of the first and second scissor blades 24, 26. The fifth layer 56 on the first blade 24 is coupled to the second electrical connection 42 and the fifth layer 56 on the second blade 26 is coupled to the first electrical connection 40. The fourth layer 54 completely separates the fifth, conductive layer 56 from the third, conductive layer 52, and the third layer has opposing polarity to the fifth layer. The fourth layer 54 is electrically nonconductive and is formed of a material that insulates against electrical current to prevent shorting between the third and fifth 52, 56 layers on the respective blades 24, 26.
With further reference to
Referring to
With continued reference to
With further reference to
Referring to
Similar to
The second layer 50 of each of the first and second scissor blades 24, 26 is coupled to the second surface 51 of the first layer 48. The third layer 52 is coupled to the second layer 50 on the side opposite the first layer 48. The third layer 52 is electrically conductive. The fourth layer 54 is coupled to the third layer 52 on the side opposite the second layer 50. The fifth layer 56 is coupled to the fourth layer 54 on the side opposite the third layer 52. The fifth layer 56 is electrically conductive.
With continuing reference to
The fifth layer 56 includes exposed portions 60 that form another first electrode 44 on each of the first and second scissor blades 24, 26. The fifth layer 56 on the first blade 24 is coupled to the first electrical connection 40 (
The third layer 52 has opposing polarity to the first and fifth layers 48, 56. The second and fourth layers 50, 54 are electrically nonconductive and are formed of materials that insulate against electrical current to prevent electrical shorting between the third layer 52 and the first and fifth layers 48, 56 on the respective blades.
With further reference to
With the first layer 48 of the first scissor blade 24 being coupled to the first electrical connection 40 and the first layer 48 of the second scissor blade 26 being coupled to the second electrical connection 42, it is necessary to electrically insulate the mating and interfacing portions of the first layer of each of the blades to prevent electrical shorting between the blades. Referring to
Similar to
With continued reference to
With further reference to
On each of the first and second scissor blades 24, 26, the distance between the at least one first electrode 44 and the at least one second electrode 46 is sufficient to prevent electrical arcing between the electrodes. At the same time, the distance between the at least one first electrode 44 and the at least one second electrode 46 is small enough to permit simultaneous connection between the tissue 22 and two respective electrodes 44, 46 having opposing polarity (see
The bipolar electrosurgical scissors 20 of the present invention may be used for numerous surgical functions, including functions that have typically been reserved for monopolar surgical devices. For example, in the first energized state, as discussed above, the scissors 20 may be used to coagulate tissue 22 between the first and second scissor blades 24, 26 prior to mechanically cutting the tissue (see
Referring to
Although this invention has been disclosed with reference to certain structural configurations, it will be appreciated that these products are merely representative of many different embodiments of the invention. Accordingly, one is cautioned not to limit the concept only to the disclosed embodiments, but rather encouraged to determine the scope of the invention only with reference to the following claims.
This application is a continuation of U.S. patent application Ser. No. 12/183,970, filed on Jul. 31, 2008, which is a continuation of U.S. patent application Ser. No. 11/460,292, filed on Jul. 27, 2006, issued on Sep. 2, 2008 and is now U.S. Pat. No. 7,419,490, the entire disclosures of which are hereby incorporated by reference as if set forth in full herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12183970 | Jul 2008 | US |
| Child | 13555609 | US | |
| Parent | 11460292 | Jul 2006 | US |
| Child | 12183970 | US |
