Abstract:
A radiowave current electrode having a shank for connection to a source of radiowave current or electrosurgical RF energy and at one end an active radiowave current electrode, the active end being shaped to perform a radiowave current procedure involving the application of the RF energy from an electrically conductive active surface of the active end to tissue to modify the tissue, the active surface having a plurality of spaced outwardly-projecting regions each shaped such that its outermost region is equal to or narrower than its innermost region, and such that more of the RF energy emanating from the active surface and passing to the tissue occurs via the outwardly-projecting regions. As a further feature, an adjacent section of the active end is coated with a substantially transparent insulating layer consisting essentially of a parylene plastic to render it inactive. As still a further feature, a thin layer of an RF excitable pigment is positioned below or mixed with the insulating layer such that when the pigment glows in response to the presence of RF on the electrode, the glow is visible to a practioner using the electrode.

Description:
[0001]    This invention relates to novel radiowave current electrodes, and in particular to radiowave current electrodes for performing various surgical procedures including nail matrixectomy, nail spicule, and other podiatry and non-podiatry procedures requiring insertion into tissue of a radiowave current electrode with adjacent active and inactive sections to selectively modulate certain tissue regions while avoiding damage to adjacent healthy tissue regions. 
       BACKGROUND OF THE INVENTION 
       [0002]    Reference is made to U.S. Pat. No. 4,517,975 (herein the “‘975 patent”, of which I am one of the inventors, the contents of which are herein incorporated by reference, for a good description for understanding the present invention. 
         [0003]    Radiowave current procedures for humans and animals are well established in the medical and dental arts. In the referenced ‘975 patent, the typical procedure (described therein as electrosurgical) involves generating a high frequency current, typically of the order of 0.5-4 MHz with a maximum output power of typically 30-150 Watts, and applying the resultant radio-frequency (RF) energy by way of an electrode to human or animal tissue. Different types of currents can be employed for different procedures. For example, fully rectified, fully filtered currents can be used for cutting tissue, fully rectified, non-filtered currents can be used for cutting with coagulation, partially rectified current can be used for hemostasis, and spark gap currents can be used for fulguration and dessication techniques. Such equipment, sometimes referred to as electrosurgical equipment, is available from many suppliers. Various electrodes configurations are also available; for example, metal needles for making incisions, wire loops, round or diamond shaped, for planing and contouring tissue, balls for coagulation and hemostasis, and scalpel shapes for incisions and excision of tissue. In many of these known electrode configurations, an electrically conductive shank, for mounting in the radiowave current handpiece, has a working end that is electrically conductive, usually metallic, and is fully exposed, so that all sides of the electrode working end are capable of transmitting the high frequency currents (herein referred to as “Radio-Frequency currents or RF energy”) to the tissue. 
         [0004]    Humans and animals can suffer from a condition commonly known as ingrown nail (hypertrophy of the unguia labia or unguis incarnatus). The nail plate is rooted under a tissue fold at the digit proximal end and grows over a nail bed or matrix toward the distal end under lateral tissue folds in the so-called lateral grooves. The healthy nail should be rooted only at the proximal end. Ingrown nail results when the nail roots under the lateral folds. This results in laceration of the adjacent tissue, with possible pain, swelling and infection. The known surgical procedure, called matrixectomy, is to excise the unwanted or extraneous root. Merely removing the nail plate section adjacent the extraneous root will not prevent recurrence of the symptoms; the entire extraneous root must be excised and precautions taken to prevent re-rooting of the nail along the lateral grooves. The nail lateral edges or margin fit snugly into the groove and normally there is a little less than 1 mm of space between the nail margin and the nail lateral wall or lip. In the RF surgical procedure described in the above-referenced ‘975 patent, a radiowave current or electrosurgical electrode with a specially designed tip whose working end is partly bare and partly insulated is used to selectively direct the RF energy by way of the bare part to only part of the tissue with which the electrode tip is in contact or is adjacent. In the preferred form as described in that patent, the electrode tip is spade shaped, one flat side of which is bare metal and the opposite flat side of which is coated with an electrical insulator. When such an electrode tip is contacted to tissue, the RF energy is supposed to exit only via the bare electrode side. Tissue facing or contacting the coated side remains unexposed and unaffected by the RF energy. 
         [0005]    Experience has indicated that in some situations, the exiting RF currents are not always confined to the flat bare side of the electrode. One problem is that the RF energy sometimes flows to the edges of the electrode (known as the “edge effect”) rather than to the middle or the total area of the exposed metal flat side. As a result there is poorer contact with the diseased tissue and the practitioner must spend more time attempting to ablate the matrix cells. This overaggressive application can cause more heat to be introduced into the cells. The result may be inconsistent matrix cell thermal ablation causing delayed nail regrowth, pain and delayed healing. 
         [0006]    Another problem that often occurs with the existing design of the matrixectomy electrode is that the Teflon coating used on the insulated side of the spade end wears quickly due to heat. Moreover, it has been shown to have low biocompatability, low dialectric strength, and a low resistance to gamma sterilization, which can introduce problems into its use with the electrosurgical electrode. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    An object of the invention is an improved electrode for carrying out radiowave current or electrosurgical procedures for modulating tissue. 
         [0008]    Another object of the invention is an improved electrode for carrying out radiowave current procedures using RF energy in which the electrode comprises active regions or sections for selectively modulating tissue with the RF energy adjacent to inactive regions or sections for protecting tissue against the RF energy. 
         [0009]    Another object of the invention is an improved surgical procedure for the removal of symptomatic spicule growth in the nail groove of a patient. 
         [0010]    Still another object of the invention is an improved electrode for the radiowave current treatment of ingrown nail. 
         [0011]    In accordance with a feature of the invention, a more efficient radiowave current electrode is obtained by including a series of furrows or corrugations or depressions or points forming plural spaced outwardly projecting regions narrower, which is preferred, or of the same size at the end than at their base in the exposed metal side of a spade-like or oval-like or flat active end of the electrode. Preferably these furrows or corrugations or depressions form spaced sharpened regions such as a point (like a sharkfin). The presence of these pointed spaced projecting regions causes the RF energy to be distributed in a more even way via these points across the active side of the electrode. 
         [0012]    The pointed furrows on the electrode spade end would also serve another important purpose. As part of the standard treatment protocol for matrixectomy, it is necessary to remove excess granulation tissue from the site. Various elevator type instruments are used for this purpose. The pointed furrows on the electrode of the invention make unnecessary these elevators as the electrode of the invention is an excellent tool to remove the granulation tissue and manually smooth the nail bed surface. 
         [0013]    In accordance with another feature of the invention, the insulating coating covering the non-active side of the electrode, typically Teflon, is replaced by an insulating plastic material known as Parylene available from Specialty Coating Systems, Inc. of Indianapolis, Ind. 46278, as well as Berwind Corporation as an SCS Micro Resist Antimicrobial Parylene Technology material, which is especially characterized for this application by excellent bio compatability, dielectric strength, excellent wear and adhesion properties, excellent resistance to gamma, and excellent chemical and moisture barrier properties. 
         [0014]    In accordance with another feature of the invention, the inactive or protected side of the electrode is coated with an RF activatable fluorescent pigment such that when the handpiece holding the electrode is activated to supply to the electrode RF energy, the RF will cause the pigment to glow and can be visually seen by the practitioner through the thin skin fold under the cuticle while carrying out a matrixectomy procedure. This avoids another problem with the existing matrixectomy electrode in that when placed under the cuticle skin fold and activated the doctor often can&#39;t tell if the electrode is receiving RF energy and actually working as intended. 
         [0015]    In accordance with another feature of the invention, a rounded electrode with a smooth surface used in a nail spicule removal procedure as described in another of my patents U.S. Pat. No. 5,683,386, whose contents are also incorporated herein by reference, is enhanced by the addition around its working end of corrugations or furrows or depressions terminating in reduced diameter spaced ends, for example, pointed ends. This improvement offers the same advantages of more uniformly spreading the RF energy where tissue ablation is desired in a more consistent manner. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0016]    The invention will now be described in greater detail with respect to several exemplary embodiments, taken in conjunction with the annexed drawings wherein: 
           [0017]      FIGS. 1-6  are perspective (from 2 different positions), side, plan, cross-section and partial perspective views, respectively, of one form of radiowave current electrode in accordance with the invention, especially useful in matrixectomy; 
           [0018]      FIGS. 7-9  are partly schematic views illustrating use of the electrode of  FIG. 1  in a nail surgical procedure; 
           [0019]      FIGS. 10-13  are perspective, end and side views, respectively, of another form of radiowave current electrode in accordance with another feature of the invention for various medical procedures; 
           [0020]      FIGS. 14-17  are perspective, end and side views, respectively, of another form of radiowave current electrode in accordance with another feature of the invention for various medical procedures; 
           [0021]      FIGS. 18, 19 and 21  are perspective, cross-sectional and side views, respectively, of another form of RF energy electrode in accordance with another feature of the invention for treating various medical problems. 
           [0022]      FIG. 20  is a perspective view of a variant of the electrode show in  FIG. 18 ; 
           [0023]      FIGS. 22 and 23  illustrate use of the electrode of  FIG. 15  in a nail matrixectomy procedure. 
           [0024]      FIGS. 24-26  are perspective and side views, respectively, of another form of radiowave current electrode in accordance with another feature of the invention for treating various medical problems. 
           [0025]      FIGS. 27-33  are views from different perspectives of another form of electrode in accordance with another feature of the invention for treating various medical problems. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0026]      FIG. 1  is a perspective view of one form of the electrode  10  according to the invention mounted in a conventional radiowave current or electrosurgical handpiece of which only the front end  12  of the handpiece is shown. The view of the electrode is similar to that shown in the ‘975 patent. In this embodiment, the electrode  10  is spade-shaped, the inactive bottom surface  14  is coated with an insulating layer  15  (not shown here), and the active surface  16 , shown schematically but in more detail in  FIG. 2  (which shows the electrode  10  in the reversed position but also with the active surface uppermost) is covered with a plurality of spaced outwardly projecting regions  18  whose outermost dimension is preferably smaller than its innermost dimension. In this embodiment, each individual region  18  (see  FIG. 6  as an example) is a polygon with slanted sides such that each outermost region is essentially a line  20  of reduced length. In this embodiment, the spaced outwardly projecting regions  18  form a series of equally spaced parallel lines. The electrode shank  22  is electrically-conductive but covered with an electrically-insulating coating  15 , and the base  17  and projections  18  of the active end are also electrically-conductive. The opposite inactive side as well as the shank is coated with an insulating layer  15  so that only the exposed side  16  with the projections  18  are electrically active (see the cross-section of  FIG. 5 ). As explained above, when the handpiece  12  is activated by the apparatus to which it is plugged into, the RF energy passes down the electrode shank to the bare active side with the projections which tend to concentrate and spread evenly the RF energy across the face of the active side so that it mainly emanates from the small area lines  20  of the projections. There are enough projections present (24 in this example) so that essentially the entire active side is electrically active, thus ensuring that the RF energy can be focused by the practitioner wherever the active side of the electrode is placed in contact with tissue. 
         [0027]    As one example only, which is not to be considered limiting, the overall length of the electrode is approximately 2-3 inches long, specifically 2 ⅜ inches in the preferred example shown, with a shank diameter of 1/16- 3/32 inches. The spade tip shown is approximately 11 mm long, which can widen from 1/16 inches wide at its proximal end to 4 mm wide at its distal end (in the  FIG. 1  embodiment, the front and rear widths of the base are alike). The uncoated tip thickness  9  is approximately 0.01 in. thick, and the insulating coating  16  has a thickness of about 0.004 in. Other shapes and thicknesses are also suitable. For matrixectomy, a suitable range of metal thickness is from about 0.006-0.050 in., and for the coating from 0.002-0.020 in. It is preferred to provide a family of four electrodes from the largest as above described down to the smallest having a maximum spade width of 1 mm, in 1 mm steps, with corresponding spade lengths of 5-11 mm. This is illustrated in  FIG. 2  with the width indicated by numeral  24 .  FIGS. 1 and 2  show essentially the same electrode with active side upright but in reversed positions for the convenience of the practioner. 
         [0028]      FIGS. 4 and 6  show a similar active end of the electrode but in which the outwardly projecting regions  18  have again been sub-divided into individual regions  18  but still aligned in parallel lines. The parallel line arrangement is not essential. The projections can be arranged in circular arrays, or in concentric circles, or even randomly spaced across the face of the active electrode side so long as enough projections are present to distribute the RF energy generally evenly across the face of the active side. 
         [0029]    The manufacture of the electrode can be conventional using standard stamping, machining and similar techniques and may be constructed of malleable metal, typically brass or stainless steel, so that the practitioner may bend it into a desired configuration. Specific techniques for forming the metallic parts are described in detail in the referenced patents as is also the preparation and application of the plastic insulating layer to the desired areas of the active end. Another way of producing the inventive structure is by conductively gluing or tightly adhering in a known way various metal fragments or particles with sharp surfaces onto the active bare electrode surface. Among the ways available are machining into the bare electrode surface, and embossing or appliquing onto the flat metal spade or oval shaped metal. Metal particles such as silver, gold, or even tungsten can be attached to the flat metal spatula or oval shaped working end by electroplating or brazing or both. The metal fragments are preferably made of a higher conductivity metal such as silver or gold so they are more likely to convey the RF energy than the lower conductivity base metal. The metal particles may typically be 5 to 100 microns in size. 
         [0030]      FIG. 5  also illustrates another feature of the invention that can be used with the embodiments described herein as well as with prior art embodiments that also use a working end that has active and inactive adjacent sections with the inactive sections coated with a plastic layer to prevent RF energy from modulating tissue that it may be in contact with during the procedure. In procedures such as matrixectomy, where the working end is inserted under tissue, sometimes it is difficult for the practioner to know whether the electrode is actually active with RF and where it is difficult to actually see the effects under the tissue. In accordance with this feature of the invention, a thin layer of an RF actuable pigment is placed under the insulating layer. The insulating layer is very thin, typically, 0.004 inches, and is virtually transparent. Therefore, if a thin layer of the pigment is placed underneath, and when it glows when RF is applied to the electrode, the glow will be visible to the practitioner through the covering plastic layer and the thin layer of skin tissue and then he or she can be assured that the active side is applying RF energy to the tissue areas desired. This is illustrated in  FIG. 5  with the thin plastic designated  15 , and the thin pigment layer underneath designated  13  and with several broken arrows  19  indicating the glow from the pigment when the electrode is activated with RF. The thin plastic layer covers and protects the pigment from being eroded as the working end is inserted and removed from under the skin fold. F fluorescent powders, commercially available, are suitable as the pigment for this purpose. It is also possible to blend the fluorescent powders with the plastic material, whether of the prior art or parylene type, so that the two are integrated into one layer. It is also possible to use shrink tubing protective covers, also mixed with the pigment, to serve as the electrically-insulating RF-responsive coating for the non-active sections. 
         [0031]      FIGS. 7-9  illustrate use of the electrode of the invention on a human or animal digit  35  in a matrixectomy procedure. The spade tip  10  is inserted under the tissue fold  26  covering the nail plate  27  edge until the bare bottom active side  16  is located over the tissue section to be destroyed, designated in dashed lines by  39 . When the radiowave current or electrosurgical equipment is energized, after appropriate grounding of the patient, eg., to patient&#39;s calf, the high frequency currents or RF energy flows through the bare outwardly projecting regions  18  of the tip  10  and into the adjacent tissue  39 . The operating conditions are chosen so as to destroy the cells adjacent the exposed active electrode side  16 . As one example, which is not to be considered limiting, power is applied for 1-2 seconds while moving the electrode. Then, the equipment is deenergized for 10-15 seconds, and power reapplied for 1-2 seconds if necessary and the procedure repeated until the extraneous root cells are destroyed. Using conventional equipment available from known manufacturing sources, it is recommended to use either the partially filtered or the fulguration current at about a 30 watt power level. Other currents and powers may be best with equipment from other suppliers, which is readily determined by simple experimentation. The tissue portions  26  abutting the upper coated side  14  of the spade tip  12  are unaffected by the high frequency currents. 
         [0032]      FIGS. 10-17  illustrate shapes other than the spade shape of  FIG. 1  of the active end that would also be suitable to treat various ingrown nail situations. In these cases, the electrode tips  40  are generally oval shaped with the top side  42  as shown provided with the plurality of spaced outwardly projecting regions  44  which preferably have smaller dimensions at the outermost tip, and preferably are generally pointed (see  FIG. 17 ). As before, the top sides  42  shown are of bare metal and the bottom inactive side is made insulating with a plastic layer  46 . The actual shape of the projecting regions  44  is not critical so long as they tend to narrow outwardly forming preferred paths for the RF energy and therefore distributing the RF more evenly across the surface than if as in the prior art the surface were smooth or flat. In the embodiments of  FIGS. 14-17 , the darker lines  47  at the oval boundaries indicate extension of the plastic layer  46  on the underside over the edges of the oval to prevent or limit the edge effect, i.e., emanation of RF energy from the edges. 
         [0033]      FIGS. 18-21  show still another suitable configuration to distribute the RF energy more uniformly over the active surface of the electrode tip. In this case, the normally smooth surface of the active end  50  is formed with three upstanding edges  52  again coming to a pointed end  54  as illustrated in  FIG. 21 . A plastic layer  53  covers the bottom inactive surface. This construction is simpler but in certain cases may not be as effective as the surface with the more numerous projections illustrated in the previous figures. 
         [0034]      FIGS. 22-23  show still another suitable configuration to distribute the RF energy more uniformly over the active surface of the electrode tip  59  again in an oval shape. In this case, the plural outstanding spaced projections  60  are concentrated along one edge  64  of the tip of the electrode. The shapes of the projections are more similar to those in the embodiments of  FIGS. 10-13  but in this embodiment are concentrated just along the edges of the active tip where the practioner may need to concentrate the RF energy under certain circumstances. But the underlying concept is similar, namely, to provide plural outstanding narrowing projections in place of the normally smooth surface of the prior art active end to distribute the RF energy more uniformly. 
         [0035]      FIGS. 24-33  show other configurations of an oval electrode tip according to the invention. In  FIGS. 24-26 , the overall shape of the electrode tip  70  is somewhat less elongated than in the embodiments of  FIG. 15  but the plural outwardly projecting projections  72  from the active side  74  are about the same shape, and as before the bottom inactive side is coated with an electrically-insulating plastic layer  76 . 
         [0036]      FIGS. 27-33  show other variations of the shape of the active tip  80  of the electrode according to the invention. In these cases, the overall shape is chisel-shaped, flat but angled to the shank  22  axis. The flat active side  82  is covered with the plurality of spaced outwardly extending projections  84  whose narrowed ends spread the RF energy more evenly across the active side of the electrode. This embodiment also illustrates the variation wherein the outwardly projections  84  are formed by conductively gluing or tightly adhering in a known way various metal fragments with sharp surfaces onto the active bare electrode surface  82 . The metal fragments  84  are given sharp edges or points and are preferably made of a higher conductivity metal such as silver or gold so they are more likely to convey the RF energy than the lower conductivity base metal. The different shapes of these tips according to the invention are useful in nail spicule and related procedures. It will also be noted that the embodiments of  FIGS. 27-33  have many more individual projections  84  than for example the embodiment of  FIG. 24 , and the size of the projections is also smaller than those in the other embodiments. This demonstrates that it is the replacement of the flat surface with the bumpy surface formed by the projections that characterizes the embodiments of the invention and provides the improved performance. 
         [0037]    Some typical examples are, for example, for the tip of  FIG. 26  a length of 11 mm. For the shapes of  FIGS. 27-33 , which can be described as chisel shaped, the length can be  8 - 10  mm with the bumpy part adding another 3 mm. The protrusion or bump  82  can be, for example 0.435 inches long and come to a point of 0.078 inches. Again, these dimensions are preferred but are not critical. For the chisel-shaped ends, with sharper pointed protrusions, some typical dimensions for the pointed ends are a height of about 0.003 inches for the points with a point spacing of about 0.006 inches. 
         [0038]    The entire electrode preferably comprises an elongated one-piece metal body having at one end the extended shank  22  and at the opposite end, the working end or tip, with opposed sides. The uncoated tip thickness  9  (perpendicular to the plane of the drawing) ( FIG. 3 ) is approximately 0.01 in. thick, and the coating  16  has a thickness of about 0.004 in. Other shapes and thicknesses are also suitable. For matrixectomy, a suitable range of metal thickness is from about 0.006-0.050 in., and for the coating from 0.002-0.020 in. It is preferred to provide a family of four electrodes from the largest as above described down to the smallest having a maximum spade width of 1 mm, in 1 mm steps, with corresponding spade lengths of 5-11 mm. The latter is illustrated in  FIGS. 2 , with the width indicated by numeral  24 . The overall tip dimensions recited in the two referenced patents are also suitable for the electrode of the present invention. The partly insulated, partly bare electrode tip of the invention with its numerous protrusions in the same or other configurations should also prove useful in other electrosurgical procedures for medical, dental or veternarian uses where the electrode tip is in contact with different tissues or tissue parts only some of which are to be selectively destroyed by currents from the bare part of the electrode tip while other contacted tissues or parts are to be preserved by the protective coating on the coated part of the electrode tip. 
         [0039]    While the invention has been described in connection with specific embodiments thereof, those skilled in the art will recognize that various modifications are possible within the principles enunciated herein and thus the present invention is not to be limited to the specific embodiments disclosed.