Patent Publication Number: US-8523856-B2

Title: Hemostasis device

Description:
This application is a continuation of U.S. application Ser. No. 12/719,714, filed Mar. 8, 2010, now U.S. Pat. No. 8,277,445, which is a continuation of U.S. application Ser. No. 11/118,653, filed Apr. 28, 2005, now U.S. Pat. No. 7,674,260, all of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This invention relates to a medical device and procedure. 
     BACKGROUND 
     A trauma victim with a wound to certain organs in the body can be at significant risk of bleeding to death if the bleeding cannot be quickly controlled. For example, the liver is formed from a parenchymatous (porous) tissue that can bleed profusely when injured. A conventional technique for controlling the bleeding is to apply immediate pressure to the tissue, however, as soon as the pressure is removed, the bleeding can resume. Gauze type products, such as QuikClot® are available, that include a hemostatic agent to promote blood clotting. However, when applied to an organ like the liver, removing the gauze can reopen the wound, leading to additional bleeding. To prevent a trauma victim from bleeding to death, bleeding must be stopped immediately and often cannot wait until a victim is transferred to a medical facility. 
     SUMMARY 
     This invention relates to a medical device and procedure. In general, in one aspect, the invention features an apparatus for substantially achieving hemostasis by tissue ablation. The apparatus includes a base member, an electrode carrier, a vacuum line and a controller. The electrode carrier is attached to a surface of the base member and includes one or more bipolar electrodes that are configured to connect to a source of radio frequency energy. The vacuum line is configured to connect to a vacuum source and to draw moisture away from the one or more bipolar electrodes during tissue ablation. The controller is electrically coupled to the electrode carrier and configured to control the delivery of radio frequency energy to the one or more bipolar electrodes, such that tissue in contact with the electrode carrier can be ablated to a desired depth of destruction to achieve substantial hemostasis. 
     In general, in another aspect, the invention features a system for substantially achieving hemostasis by tissue ablation. The system includes a hemostasis device, a source of radio frequency, a controller and a vacuum source. The hemostasis device includes a base member, an electrode carrier and a vacuum line. The electrode carrier is attached to a surface of the base member and includes one or more bipolar electrodes. The one or more bipolar electrodes are configured to connect to the source of radio frequency energy. The vacuum line is configured to connect to the vacuum source. The source of radio frequency energy is electrically coupled to the one or more bipolar electrodes. The controller is configured to control the delivery of radio frequency energy from the source of radio frequency energy to the one or more bipolar electrodes, such that tissue can be ablated to a desired depth of destruction to achieve substantial hemostasis. The vacuum source is coupled to the vacuum line and operable to draw bleeding tissue into contact with the electrode carrier and to draw moisture generated during delivery of radio frequency energy to the one or more bipolar electrodes and ablation of the tissue away from the one or more bipolar electrodes, and to substantially eliminate liquid surrounding the one or more bipolar electrodes. 
     Implementations of the system or apparatus can include one or more of the following features. The apparatus can further include a porous layer positioned between the base member and the electrode carrier, the porous layer coupled to the vacuum line. The base member and the electrode carrier attached thereto can be substantially flexible, alternatively, the base member can be substantially rigid. In one embodiment, the base member is a glove including a palm region and finger regions and the electrode carrier is attached to the palm region of the base member. The glove can include one or more additional electrode carriers attached to the finger regions. 
     The electrode carrier can include woven strips of a non-conductive material, where the one or more bipolar electrodes include electrode wires woven in a first direction between the strips of non-conductive material. In one embodiment, sets of two or more electrode wires are woven in a first direction between each strip of non-conductive material orientated in the first direction, where each set of electrode wires alternates polarity, and a pair of sets of electrode wires comprises a bipolar electrode. The base member can be substantially cylindrically shaped, and the electrode carrier attached to an exterior surface of the cylindrically shaped base member. A second electrode carrier can be attached to an interior surface of the cylindrically shaped base member. 
     In general, in another aspect, the invention features a method for blood coagulation. An electrode carrier of a hemostasis device is positioned in contact with bleeding tissue. The hemostasis device includes a base member, the electrode carrier attached to a surface of the base member, the electrode carrier including one or more bipolar electrodes connected to a source of radio frequency energy, and a vacuum line connected to a vacuum source. A vacuum source is activated to draw the bleeding tissue into closer contact with the electrode carrier and to draw moisture released from the tissue during ablation away from the one or more bipolar electrodes. The source of radio frequency energy is activated and radio frequency energy is delivered to the one or more bipolar electrodes and ablates the tissue in contact with the one or more bipolar electrodes. The delivery of the radio frequency energy is ceased upon reaching a desired depth of destruction of the tissue. Hemostasis is substantially achieved in a region of the ablation. 
     In general, in another aspect, the invention features an apparatus for achieving hemostasis by tissue ablation including a base member shaped as a glove configured to be worn by a user. The apparatus further includes an electrode carrier attached to a surface of the base member and a controller. The electrode carrier includes one or more bipolar electrodes that are configured to connect to a source of radio frequency energy. The controller is electrically coupled to the electrode carrier and configured to control the delivery of radio frequency energy to the one or more bipolar electrodes, such that tissue in contact with the electrode carrier can be ablated to a desired depth of destruction to achieve substantial hemostasis. 
     Implementations of the apparatus can include one or more of the following. A porous layer can be positioned between the base member and the electrode carrier, the porous layer including a vacuum line configured to connect to a vacuum source and to draw moisture away from the one or more bipolar electrodes during tissue ablation. The base member can include a palm region and finger regions and the electrode carrier can be attached to the palm region of the base member. The apparatus can include one or more additional electrode carriers attached to undersides of the finger regions of the base member. The base member can include a main region corresponding to the hand of a glove and finger regions corresponding to fingers of a glove where the electrode carrier is attached to a top side of the main region opposite to a palm side of the main region. One or more additional electrode carriers can be attached to top sides of the finger regions of the base member. 
     The electrode carrier or carriers can include woven strips of a non-conductive material, where the one or more bipolar electrodes include electrode wires woven in a first direction between the strips of non-conductive material. In another embodiment, sets of two or more electrode wires are woven in a first direction between each strip of non-conductive material orientated in the first direction, where each set of electrode wires alternates polarity, and a pair of sets of electrode wires is a bipolar electrode. 
     Implementations of the invention can realize one or more of the following advantages. Hemostasis, the stoppage of bleeding, can be achieved quickly and in difficult to access locations in a patient&#39;s body. The hemostasis device can be used in trauma situations, such as the battleground, accident scenes or an emergency room, to quickly control bleeding and prevent the patient from bleeding to death. Tissue types that can bleed profusely and are difficult treat can be treated using the hemostasis device. The liver is a good example, as bleeding from the liver can be difficult to control, even under operating room conditions. The hemostasis device can have different configurations that are suited to different applications, for example, the device can be flexible, rigid, shaped as a glove, shaped cylindrically, etc. The depth of destruction of the tissue can be controlled so as to desiccate and coagulate the superficial tissue, without causing additional or unnecessary injury. The electrode carrier on the hemostasis device can be removed without restarting the bleeding, nor does pressure need to be applied after desiccation is complete. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a schematic representation of a hemostasis device. 
         FIG. 1B  is a schematic representation of an alternative embodiment of the hemostasis device of  FIG. 1A . 
         FIG. 2  is an enlarged view of a portion of an electrode carrier. 
         FIG. 3  is an enlarged cross-sectional view of a portion of an electrode carrier. 
         FIG. 4  is a schematic representation of a system including a hemostasis device. 
         FIG. 5  is a side view of a portion of a hemostasis device in contact with tissue. 
         FIG. 6  is a flowchart showing a process for coagulating blood using a hemostasis device. 
         FIGS. 7A-D  are schematic representations of cross-sectional views showing electrodes in contact with tissue for ablation. 
         FIG. 8  is a schematic representation of an alternative embodiment of a hemostasis device. 
         FIG. 9  is a schematic representation of another alternative embodiment of a hemostasis device. 
         FIG. 10  is a schematic representation of a cylindrically shaped embodiment of a hemostasis device. 
     
    
    
     Like reference symbols in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     A method and system for achieving hemostasis (the stoppage of bleeding) is described. RF (radio frequency) energy is used to ablate the surface of tissue to stop bleeding. The depth of destruction of the tissue can be controlled so as to desiccate and coagulate the superficial tissue, without causing additional or unnecessary injury. An electrode carrier including bipolar electrodes can be applied to the tissue, and RF energy transmitted through the bipolar electrodes to ablate the tissue. A layer of desiccated tissue, e.g., approximately 1 mm thick, can be created as well as coagulation of the tissue to achieve hemostasis. The electrode carrier can be removed without restarting the bleeding, nor does pressure need to be applied after desiccation is complete. 
     Referring to  FIG. 1A , one embodiment of a hemostasis device  100  is shown. The base member of the hemostasis device  100  is configured as a glove and includes one or more electrode carriers. In the embodiment shown, a first electrode carrier  102  is included in the palm of the glove shaped hemostasis device  100 , and five narrower electrode carriers  104 - 112  are included on the fingers and thumb of the hemostasis device  100 . The glove-shaped hemostasis device  100  can fit over a user&#39;s hand, and is flexible so that the fingers can be extended or curled, etc., as desired by the user. The electrode carriers can have different configurations, e.g., the electrodes can extend along the proximal and/or distal ends of the palm and/or fingers. 
     Referring to  FIG. 1B , in another embodiment of the hemostasis device  101 , the electrode carriers are on the exterior surface of the glove shaped device, i.e., on the “top side” of the hand rather than on the “palm side”. In the embodiment shown, a first electrode carrier  103  is included on the top of the glove shaped hemostasis device  101 , and five narrower electrode carriers  105 - 113  are including on the tops of the fingers and thumb. In one application, a user can position the hemostasis device  101  within a cavity, e.g., a uterus, and form a first to achieve hemostasis of the tissue within the cavity. In yet another embodiment, electrode carriers can be included on both the palm side and top side of the glove shaped device, or can be included on the fingers only or the palm and top of the hand only. Other configurations are possible. 
     Referring again to  FIG. 1A  and to  FIG. 2 , an enlarged view is shown of a portion of the first electrode carrier  102 . The electrode carrier  102  is formed from a woven insulative base material  114 , which in one embodiment can be thin, plastic strips. Woven between the strips of base material  114  are electrodes  116 . In this embodiment, the electrodes  116  are gold plated copper wires and two electrodes  116  are woven between each strip of base material  114 . The electrodes  116  can be oppositely charged between each strip of base material  114 . That is, electrodes  116   a  can be positively charged, and electrodes  116   b  can be negatively charged, with the strip of base material  114  providing a non-conductive region between the bi-polar electrode regions  116   a ,  116   b . In another embodiment, a single electrode  116  can be woven between each strip of base material  114 , with each electrode  116  alternating conductivity. In yet another embodiment, more than two electrodes  116  can be woven between each strip of base material. A pair of oppositely charged electrodes (or a pair of sets of electrodes) is referred to herein as a “bipolar electrode”. Referring again to  FIG. 1A , the electrodes  116  are electrically coupled to a connector  118  that can be electrically coupled by a cable  120  to an RF generator. 
     Referring to  FIG. 3 , a cross-sectional view is shown of the portion of the first electrode carrier  102  shown in  FIG. 2  taken along line  3 - 3 . The body  122  of the glove shaped hemostasis device  100  can be formed from a relatively thin and flexible material, e.g., nylon. As part of the body  122 , or as a separate layer, a thermally insulating layer is included to protect the user&#39;s hand from temperatures generated during use of the hemostasis device  100  (e.g., from steam created from tissue desiccation). The electrode carrier  102  includes a porous layer  124  between the body  122  of the glove and the strips of base material  114  and electrodes  116 . A vacuum line  126  is included within or under the porous layer  124  and is coupled to a vacuum port  128  that can be connected by a fluid line  130  to a vacuum source ( FIG. 1 ). The porous layer  124  is configured such that when vacuum is applied through the vacuum line  126 , tissue can be drawn into contact with the electrode carrier  102 ; the porous layer  124  facilitates spreading the vacuum over the surface of the electrode carrier  102 . In one embodiment, the porous layer  124  can be formed from nylon and/or spandex. An electrode  116  is shown woven between the strips of base material  114 . 
     Referring to  FIG. 4 , a system is shown including the hemostasis device  100 , an RF generator  140  and a vacuum source  142 . The RF generator  140  is coupled to the hemostasis device  100  by the cable  120 . The vacuum source  142  is coupled to the hemostasis device  100  by the fluid line  130 . In one embodiment, as shown, the vacuum source  142  can be activated by a foot pedal  144 , to allow an operator of the hemostasis device  100  to keep both hands free to work with the bleeding tissue. In another embodiment, the RF generator  140  and the vacuum source  142  are combined into a single RF controller unit, which includes the RF generator, vacuum source, a vacuum monitoring system as well as a foot pedal  144  for activating both the RF energy and the vacuum. Additionally, a user input device including a display (e.g., similar to user input device  146  shown) can be included in the single RF controller unit. 
     In one embodiment, an operator can control which electrode carriers  102 - 112  are activated when using the hemostasis device  100 . That is, for a particular application, using the palm electrode carrier  102  alone may be desirable. In an alternative application, for example, where a finger electrode carrier  106  can be placed over a cut in damaged tissue, it may be desirable to only activate the finger electrode carrier  106 , so as not to unnecessarily ablate healthy (i.e., undamaged) tissue in contact with other parts of the hemostasis device  100 . The RF generator  140  can be connected to a user input device  146  to receive instructions from a user as to which electrode carriers to activate. 
     In the embodiment shown, the user input device  146  includes a touch screen display  148 . A visual representation of the hemostasis device  100  is shown on the touch screen display  148 . Each electrode carrier on the hemostasis device  100  is represented by a corresponding graphic representation on the touch screen display  148 . Once touched, the electrode carrier graphic becomes highlighted, indicating it has been selected, and by touching the graphic a second time, the electrode carrier is deselected. For example, by touching an area of the touch screen display  148  representing the palm electrode carrier  102 , the RF generator, when activated (e.g., by depressing a foot pedal  144 ), is instructed to transmit RF energy to the palm electrode carrier  102 . 
     In one implementation, routing the RF energy in this manner can be accomplished by having separate electrical connections, or pins, from the RF generator to each electrode carrier. Selecting a certain electrode carrier on the touch screen display  148  instructs the RF generator to close the switch to the pin of the corresponding electrode carrier on the hemostasis device  100 . In this manner, once RF energy is initiated, the RF energy flows to only those electrode carriers that have been selected on the touch screen display  148 . The user can select to activate some or all of the six electrode carriers  102 - 112 . In one embodiment, conventional touch screen technology can be used to implement the touch screen display  148 . Other types of user input devices  146  can be used, and the touch screen display  148  is just one example. 
       FIG. 5  shows a side view of the hemostasis device  100  in contact with damaged tissue  150 . Referring to  FIG. 6 , a process  200  for using the hemostasis device  100  to stop bleeding from the damaged tissue  150  shall be described for illustrative purposes. The hemostasis device  100  is first positioned by the user in contact with the damaged tissue  150  (step  202 ). The user can exercise his/her discretion as to how the hemostasis device  100  is positioned, depending on the configuration of the tissue  150  to be treated. For example, the electrode carriers to be activated can be selected by the user or an assistant selectively touching the corresponding areas on the touch screen display  148  (step  204 ). The vacuum source  142  is activated, e.g., by depressing foot pedal  144  (step  206 ), causing the damaged tissue  150  to be drawn into closer contact with the hemostasis device  100 , and simultaneous evacuation of blood, vapors and/or other material. The RF generator  140  receives the input from the user input device  146  and transmits RF energy to the selected electrode carrier  102  (step  206 ). 
     The damaged tissue  150  is ablated in the area in contact with the electrode carrier  102  until a desired depth of destruction is reached (step  208 ). The region  152  depicted in  FIG. 5  represents the desiccated tissue. The RF energy and vacuum are ceased (step  210 ) and the hemostasis device  100  can be removed from the tissue  150  (step  212 ). Ablating the upper surface of the bleeding tissue, e.g., to a depth of approximately 1 to 7 mm, depending upon the type of tissue treated, desiccates and coagulates the tissue and achieves hemostasis. Because the bleeding has ceased due to desiccation of the tissue, rather than due to the application of pressure, the hemostasis device can be removed without restarting the bleeding. Optionally, a non-stick coating can be applied to the surface of the hemostasis device  100  to promote separation from the tissue after hemostasis is achieved and the procedure is complete. 
     To achieve the desired depth of ablation, a controller included in the RF generator  140  can monitor the impedance of the tissue at the electrodes  116  and include an automatic shut-off once a threshold impedance is detected. As the tissue  150  is desiccated by the RF energy, fluid is lost and withdrawn from the region by the vacuum  140  into the porous layer  124  and removed through the vacuum line  126 . The vacuum draws moisture released by the tissue undergoing ablation away from the electrode carrier  102  and prevents formation of a low-impedance liquid layer around the electrodes  116  during ablation. As more of the tissue is desiccated, the higher the impedance experienced at the electrodes  116 . By calibrating the RF generator  140 , taking into account system impedance (e.g., inductance in cabling, etc.) and electrode carrier configuration (e.g., center-to-center distance between electrodes  116 ), a threshold impedance level can be set that corresponds to a desired depth of ablation. Once the threshold impedance is detected, the controller shuts off the RF energy, controlling the depth of tissue destruction. In an alternative embodiment, the RF generator  140  can be designed such that above the threshold impedance level the RF generator&#39;s ability to deliver RF energy is greatly reduced, which in effect automatically terminates energy delivery. 
     The depth of destruction is a function of a number of factors, including the tissue impedance, center-to-center distance between the positive and negative electrodes of a bipolar electrode and the surface density of the electrodes, as described further below. In one implementation, the user input device  146  can be configured to permit a user to select the depth of destruction, for example, by selecting the surface density of electrodes and/or center-to-center distance between the electrodes. 
     As described above in reference to  FIG. 2 , more or fewer electrodes  116  can be woven between each strip of base material  114 , thereby increasing the surface density of the electrodes  116 . If greater ablation depth is desired, more electrodes  116 , e.g., five, can be woven between each strip of base material  114 . Additionally, increasing the center-to-center distance between the positive electrode and negative electrode of a bipolar electrode can increase the depth of destruction. In the present example, a first set of five electrodes  116  can be positively energized and the adjacent set of five electrodes  116  negatively energized, which pattern is repeated across the electrode carrier  102 . The entire grouping of 10 electrodes, i.e., the 5 positive and 5 negative electrodes, together are one bipolar electrode. The center-to-center distance between the set of positive electrodes and set of negative electrodes is thereby increased, which can increase the depth of ablation. 
     Referring to  FIG. 7A , preferably each electrode is energized at a polarity opposite from that of its neighboring electrodes. By doing so, energy field patterns, designated  222 ,  224  and  226  in  FIG. 7A , are generated between the electrode sites and thus help to direct the flow of current through the tissue T to form a region of ablation A. As can be seen in  FIG. 7A , if electrode spacing is increased by energizing, for example, every third or fifth electrode  220  rather than all electrodes, the energy patterns will extend more deeply into the tissue. See, for example, pattern  224  which results from energization of electrodes having a non-energized electrode between them, or pattern  226  which results from energization of electrodes having two non-energized electrodes between them. 
     The depth of ablation is also effected by the electrode density (i.e., the percentage of the target tissue area which is in contact with active electrode surfaces) and may be regulated by pre-selecting the amount of this active electrode coverage. For example, the depth of ablation is much greater when the active electrode surface covers more than 10% of the target tissue than it is when the active electrode surfaces covers only 1% of the target tissue. 
     By way of illustration, by using 3-6 mm spacing and an electrode width of approximately 0.5-2.5 mm, delivery of approximately 20-40 watts over a 9-16 cm 2  target tissue area will cause ablation to a depth of approximately 5-7 millimeters when the active electrode surface covers more than 10% of the target tissue area. After reaching this ablation depth, the impedance of the tissue will become so great that ablation will self-terminate. By contrast, using the same power, spacing, electrode width, and RF frequency will produce an ablation depth of only 2-3 mm when the active electrode surfaces covers less than 1% of the target tissue area. This can be better understood with reference to  FIG. 7B , in which high surface density electrodes are designated  220 A and low surface density electrodes are designated  220 B. For purposes of this comparison between low and high surface density electrodes, each bracketed group of low density electrodes is considered to be a single electrode. Thus, the electrode widths W and spacings S extend as shown in  FIG. 7B . 
     As is apparent from  FIG. 7B , the electrodes  220 A, which have more active area in contact with the underlying tissue T, produce a region of ablation A 1  that extends more deeply into the tissue T than the ablation region A 2  produced by the low density electrodes  220 B, even though the electrode spacings and widths are the same for the high and low density electrodes. Some examples of electrode widths, having spacings with more than 10% active electrode surface coverage, and their resultant ablation depth, based on an ablation area of 6 cm 2  and a power of 20-40 watts, are given on the following table: 
     
       
         
           
               
               
               
             
               
                   
               
               
                 ELECTRODE WIDTH 
                 SPACING 
                 APPROX. DEPTH 
               
               
                   
               
             
            
               
                    1 mm 
                 1-2 mm 
                 1-3 mm 
               
               
                 1-2.5 mm 
                 3-6 mm 
                 5-7 mm 
               
               
                 1-4.5 mm 
                 8-10 mm  
                 8-10 mm  
               
               
                   
               
            
           
         
       
     
     Examples of electrode widths, having spacings with less than 1% active electrode surface coverage, and their resultant ablation depth, based on an ablation area of 6 cm 2  and a power of 20-40 watts, are given on the following table: 
     
       
         
           
               
               
               
             
               
                   
               
               
                 ELECTRODE WIDTH 
                 SPACING 
                 APPROX. DEPTH 
               
               
                   
               
             
            
               
                    1 mm 
                 1-2 mm 
                 0.5-1 mm   
               
               
                 1-2.5 mm 
                 3-6 mm 
                 2-3 mm 
               
               
                 1-4.5 mm 
                 8-10 mm  
                 2-3 mm 
               
               
                   
               
            
           
         
       
     
     Thus it can be seen that the depth of ablation is significantly less when the active electrode surface coverage is decreased. 
     Referring to  FIG. 7C , if multiple, closely spaced, electrodes  220  are provided on the electrode carrying member, a user may set the RF generator  140  to energize electrodes which will produce a desired electrode spacing and active electrode area. For example, alternate electrodes may be energized as shown in  FIG. 7C , with the first three energized electrodes having positive polarity, the second three having negative polarity, etc. All six electrodes together can be referred to as one bipolar electrode. As another example, shown in  FIG. 7D , if greater ablation depth is desired the first five electrodes may be positively energized, and the seventh through eleventh electrodes negatively energized, with the sixth electrode remaining inactivated to provide adequate electrode spacing. A user can therefore not only control which electrode carriers are activated, but in one implementation can also control which electrodes are energized within an electrode carrier to produce a desired depth of destruction. 
     Other embodiments of the one or more electrode carriers are possible. For example, referring to  FIG. 8 , in one embodiment, an electrode carrier, e.g., the palm electrode carrier  302 , can be formed of a fabric that is metallized in regions to form the electrodes  316 . The electrodes  316  are conductive and alternate between positive and negative polarity. Non-conductive insulator regions  318  separate the electrodes  316 . For example, the fabric can be a composite yarn with a thermoplastic elastomer (TPE) core and multiple polyfilament nylon bundles wound around the TPE as a cover. The nylon bundles are plated with thin, conductive metal layers. This construction is flexible, and can facilitate achieving close contact between the electrode carrier  302  and an irregularly shaped area of tissue. Other configurations for the electrode carriers  102 - 112  are possible, and the above described embodiments are merely exemplary electrode carriers. 
     The hemostasis device has been described with reference to an embodiment where the electrode carrier or carriers are on the surface of a glove that can be worn by a user. Other embodiments of the base member of the hemostasis device are possible. For example, referring to  FIG. 9 , in one embodiment the base member  400  can be a paddle with a handle. One or more electrode carriers  402  can be affixed to the surface of the paddle  400 , which can be manipulated by a user into a position in contact with damaged tissue. A porous layer is included beneath the electrode carrier  402  and a vacuum source can be connected to a vacuum line within or under the porous layer to provide vacuum at the electrode carrier surface, as described above in reference to the glove-shaped embodiment. 
     In one embodiment, the paddle  400  can be formed smaller than a human hand, such that the paddle  400  can reach into areas that might otherwise be inaccessible by a human hand if using the glove-configured hemostasis device  100 . In another embodiment, the paddle  400  and electrode carrier  402  can be formed larger than the palm of a human hand, such that the electrode carrier  402  can be used to cover relatively large areas of damaged tissue, i.e., larger than can be covered by the palm electrode carrier  102  of the glove-configured hemostasis device  100 . Other configurations of the hemostasis device are possible, including different shapes and sizes. The paddle  400 , or otherwise configured base member, can be flexible so as to conform to the surface of damaged tissue, or can be substantially rigid, which may be desirable in certain applications. 
     The hemostasis device can be used to achieve hemostasis under urgent, life-threatening conditions, e.g., on a battlefield or at the scene of an accident, or under controlled conditions, e.g., during surgery. For example, a soldier suffering an injury to the liver on the battlefield is often at risk of bleeding to death within a considerably short period of time. The liver is an organ that once damaged can bleed profusely, and the surface is such that the liver cannot simply be sutured to stop bleeding. The hemostasis device, for example the glove-shaped hemostasis device  100 , can be ideal in such situations. A user, even under battlefield conditions, can put on the glove-shaped hemostasis device  100 , reach into the soldier&#39;s body, find the damaged liver, activate the desired one or more electrode carriers, and achieve hemostasis in a very short period of time. A soldier who may have otherwise bled to death could be saved using the hemostasis device  100 . 
     The hemostasis device can also be useful in surgical procedures. By way of illustrative example, consider a liver that has been diagnosed as including a tumor that must be removed to save a patient&#39;s life. Using conventional techniques, to remove the tumor one or more incisions into the liver would be necessary. Cutting into the liver tissue typically triggers profuse bleeding that can be difficult to control, even under operating room conditions. The hemostasis device can instead be used to achieve almost immediate hemostasis, avoiding unnecessary blood loss from the patient. For example, after making an incision into the liver, a user wearing the glove-shaped hemostasis device  100  can lay a finger over the incision and activate the electrode carrier corresponding to the finger. RF energy transmitted to the activated electrode carrier can quickly achieve hemostasis. 
     In an alternative implementation, the base member of the hemostasis device  500  can be cylindrically shaped as shown in  FIG. 10 . One or more bipolar electrodes  504  can be positioned on the exterior surface of the hemostasis device  500 . A cable  508  can connect the one or more bipolar electrodes  504  to an RF energy source, and a fluid line  506  can connect a porous layer beneath the bipolar electrodes to a vacuum source. Optionally, a distal end  502  of the hemostasis device  500  can be sharpened so the hemostasis device  500  can cut into the tissue while being inserted into position. The hemostasis device  500  can be inserted into tissue, for example, a liver including a tumor, so that the tumor is within the interior of the hemostasis device  500  when it is positioned in the liver. The one or more bipolar electrodes  504  on the exterior of the hemostasis device  500  can be activated, and the surrounding tissue ablated. The hemostasis device  500  and the tissue within the interior core can be removed from the liver. The tumor is thereby extracted from the liver, and hemostasis in achieved in the surrounding tissue. In another embodiment, one or more bipolar electrodes can be included on the interior of the hemostasis device  500 . Other configurations are possible. 
     Other embodiments of the base member and hemostasis device are possible, and the ones described above are merely exemplary. Additionally, other procedures for using the hemostasis device are possible, and the battlefield and surgical procedures described above were examples for illustrative purposes. 
     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.