Abstract:
An apparatus for aiding coagulation of fluids and tissue during surgery is provided. The apparatus includes a suction tube and first and second electrodes shaped as a cylindrical section extending from the suction tube. Two spaces are formed between the first electrode and the second electrode, and the distance between the tips of the electrodes and the suction tube is large enough to allow unobstructed viewing of the tissue that is being treated.

Description:
FIELD OF THE INVENTION 
     The present invention relates to electrosurgical coagulation instruments and systems for treating human or animal biological tissue using radio-frequency energy. More specifically, the present invention relates to surgical devices and methods for applying radio-frequency energy to coagulate blood and desiccate tissues in combination with the facility to suction fluids and suspended materials from the surgical site. 
     BACKGROUND OF THE INVENTION 
     Numerous surgical instruments for the treatment of biological tissues through the application of energy in medical procedures are known in the art. Such prior art devices use wire-loop electrodes shaped to enhance current density where employed, resulting in high power densities in the affected tissues. These prior art devices are adapted to cause tissue ablation by burning, cauterization, or otherwise damaging the tissue. While such devices are useful for such purposes, they have no other recognized uses. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a surgical instrument is provided that allows tissue to be treated to coagulate bodily fluids during surgery using radio frequency electrical energy. 
     In accordance with an exemplary embodiment of the present invention, an apparatus for aiding coagulation of fluids in tissue during surgery is provided. The apparatus includes a suction tube and first and second electrodes shaped as a cylindrical section extending from the suction tube. Two spaces are formed between the first electrode and the second electrode, and the distance between the tips of the electrodes and the suction tube is large enough to allow unobstructed viewing of the tissue that is being treated. 
     The present invention provides many important technical advantages. One important technical advantage of the present invention is a surgical instrument that allows tissue to be treated with radio frequency energy in a manner that does not obstruct viewing of the tissue during treatment and which allows gasses, particulates and fluids to be removed. 
     Those skilled in the art will further appreciate the advantages and superior features of the invention together with other important aspects thereof on reading the detailed description that follows in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a surgical instrument for coagulating blood and providing suction in accordance with an exemplary embodiment of the present invention; 
         FIG. 2  is a diagram of a front view of a surgical instrument in accordance with an exemplary embodiment of the present invention; 
         FIG. 3  is a diagram of a section view of a surgical instrument in accordance with an exemplary embodiment of the present invention; 
         FIG. 4  is a diagram of two views A and B of a connector for a surgical instrument in accordance with an exemplary embodiment of the present invention; 
         FIG. 5  is a diagram of a connector for a surgical instrument with an electrosurgical generator control in accordance with an exemplary embodiment of the present invention; 
         FIG. 6  is an alternate view of a connector for a surgical instrument with an electrosurgical generator control in accordance with an exemplary embodiment of the present invention; 
         FIG. 7  is a diagram of electrodes in accordance with an exemplary embodiment of the present invention; and 
         FIG. 8  is a diagram of a system in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawing figures might not be to scale and certain components can be shown in generalized or schematic form and identified by commercial designations in the interest of clarity and conciseness. 
       FIG. 1  is a diagram of a surgical instrument  100  for coagulating blood and providing suction in accordance with an exemplary embodiment of the present invention. 
     Surgical instrument  100  coagulates bleeding wounds while providing a mechanism for removing gaseous, particulate solids and liquids, such as serous materials, from the site of treatment. Surgical instrument  100  includes electrodes  102  and  104 , which are rounded or chamfered so as to provide adequate current distribution and sufficient surface area in order to reduce or eliminate the high power densities that produce char and smoke, the products of vaporization and ablation. Electrodes  102  and  104  are set in relationship to each other to reduce electrode to electrode current flow and to promote a current pathway through the target tissues. Electrodes  102  and  104  are of sufficient prominence as to allow for the shallow angles of incidence demanded by tight spaces. Surgical instrument  100  delivers lower levels of energy over an area larger than those depicted in prior art with the intent of keeping tissue temperatures below 200 degrees Centigrade, ideally below 120 degrees Centigrade to avoid charring and collateral damage to adjacent tissues and structures. 
     In addition, electrodes  102  and  104  support suction tube  106  away from the tissue that is being treated while allowing visual access to the tissue, so as to allow the practitioner that is using surgical instrument  100  to be able to determine whether the tissue has been sufficiently coagulated, whether tissue charring is occurring, or whether other treatment is required. The structure of electrodes  102  and  104  further provides a channel to help direct the flow of gasses, particulates and fluids into suction tube  106 , so as to facilitate coagulation. Suction tube  106  can be constructed of non-conductive materials, can be constructed of metal and a non-conductive tip with electrodes  102  and  104  embedded into it, or can be constructed in other suitable manners. In one exemplary embodiment, suction tube  106  is constructed from metal soft enough to allow for ad hoc bending by the operator during use. 
     In one exemplary embodiment, the non-conducting surfaces of electrodes  102  and  104  and the inner and outer walls of suction tube  106  can be coated with Teflon™ (PTFE), tungsten disulfide or other “non-stick” coatings, to reduce the need for repeated cleaning of surgical instrument  100  during its use during a procedure. Conductive materials can be disposed in the non-stick coating, the non-stick coating can be applied or treated so as to create small conducting pathways, or other suitable processes can be used to allow the electrodes to conduct electricity with the non-stick coating. 
     Surgical instrument  100  is compatible with suitable bipolar electrosurgical generators on the market. However, unlike prior art devices that are designed for use with such bipolar electrosurgical generators, which are used to ablate tissue and then suction it away, surgical instrument  100  is optimized to reduce or eliminate tissue destruction. In particular, electrodes  102  and  104  are configured to avoid current concentration, electrical field concentration, power concentration, or other effects that are optimized in prior art system in order to cause tissue ablation, such as by increasing the electrode surface area so as to provide a larger tissue contact area, by electrode shaping, or by other suitable factors. Electrodes  102  and  104  provide uniform current, electrical field, and power so as to aid in coagulation without tissue ablation. Suction is applied primarily to draw away blood, so as to provide a dry field to aid in coagulation. In addition to increasing electrode surface area, lower frequency voltages are applied to reduce tissue ablation and aid in coagulation, the lower limit being determined by the occurrence of muscle stimuli. As such muscle stimuli typically occurs at frequencies below several hundred hertz, and as tissue ablation is typically performed using fundamental frequencies above several hundred kHz, the operator can be given increased selectivity of fundamental frequency control within the range of several hundred to several thousand hertz. Likewise, operator control is provided for voltage levels, current levels, power levels, voltage waveforms, and other operating parameters. 
       FIG. 2  is a diagram of a front view of surgical instrument  100  in accordance with an exemplary embodiment of the present invention. The curvature of electrodes  102  and  104  is aligned with suction tube  106 , so as to facilitate the flow of gasses and fluids through central suction lumen  202 . In addition, the shape of electrodes  102  and  104  helps to control the voltage and current distribution in the tissue between the electrodes so as to avoid concentration of heating in tissue. 
       FIG. 3  is a diagram of a section view of surgical instrument  100  in accordance with an exemplary embodiment of the present invention. Embedded conductors  302  and  304  provide electrical current and voltage to electrodes  102  and  104 . Suction tube  106  can be fabricated from an insulating material, insulation can be provided for embedded conductors  302  and  304  where suction tube  106  is fabricated from a conducting material, or other suitable configurations can be used to insulate conductors  302  and  304  from suction tube  106  and each other. Gasses, fluids and particulates are conducted in the direction of arrows  306  and are removed to a suitable container. 
       FIG. 4  is a diagram of two views A and B of a connector  400  for surgical instrument  100  in accordance with an exemplary embodiment of the present invention. Connector  400  includes electrical connectors  402 A and  402 B, which are electrically connected to conductors  302  and  304 . Suction control port  404  allows the amount of suction to be controlled, so as to increase the volume of air for cooling, to adjust the amount of suction based on the amount of gas, particulate solids, or fluids that need to be removed, or for other suitable purposes. Instrument body  406  includes ergonomic grips to allow the user to maintain a firm grip on surgical instrument  100  under moist conditions and to reduce fatigue. Suction tubing connector  408  allows surgical instrument  100  to be connected to a source of suction. 
       FIG. 5  is a diagram of connector  500  for a surgical instrument with electrosurgical generator control in accordance with an exemplary embodiment of the present invention. Connector  500  includes radio frequency current pins  502 , which provide radio frequency electrical energy to the electrodes  102  and  104 , and electrosurgical generator control pins  504 , which allow the operator to control the power delivered to the tissue through the electrodes. In addition, electrosurgical generator control  504  allows the operator to control the application of power to the electrodes  102  and  104 . In one exemplary embodiment, electrosurgical generator control  504  can be an on/off switch, a thumb dial, or other suitable controls. 
       FIG. 6  is alternate view of connector  500  for a surgical instrument with electrosurgical generator control in accordance with an exemplary embodiment of the present invention. As shown in  FIG. 6 , the radio frequency current pins  502  and electrosurgical generator control pins  504  extend at a right angle to suction port  404  and electrosurgical generator control  504 , so as not to interfere with the operation of the controls. 
       FIG. 7  is a diagram of electrodes  700  and  702  in accordance with an exemplary embodiment of the present invention. Electrodes  700  and  702  have rounded corners so as to avoid concentration points, where current density can cause tissue burning, and to distribute the electrical field generated between the electrodes in a uniform manner. 
       FIG. 8  is a diagram of system  800  in accordance with an exemplary embodiment of the present invention. System  800  includes bipolar generator  802 , which is coupled by power cord  804  to connector  400  or  500 . A suction tube  806  is also coupled to connector  400  or  500 , and carries gaseous, particulate solids and liquids, such as serous materials, from the site of treatment to container  808 , which can include baffles, filters, or other suitable materials to prevent such materials from being carried on to a suction generator (not explicitly shown) that is connected to container  808  by suction tube  810 . A footswitch  812  can be used by the operator, either alone or in conjunction with electrosurgical generator control  504 , to allow the operator to control the power being provided to the treated tissue. In one exemplary embodiment, the footswitch  812  can be used to control power, frequency, voltage, current, waveform, or other suitable variables. For example, footswitch  812  can be configured to allow the operator to control the frequency of the applied electricity from a low of several hundred Hz to a high of several thousand Hz, so as to allow the operator to prevent tissue ablation without causing muscle stimulation. The suction is controlled using the small slot in the top of the instrument. 
     Although exemplary embodiments of a system and method of the present invention have been described in detail herein, those skilled in the art will also recognize that various substitutions and modifications can be made to the systems and methods without departing from the scope and spirit of the appended claims.