MX2008004552A - Methods and systems for determining physiologic characteristics for treatment of the esophagus - Google Patents

Abstract

A method and apparatus for treating abnormal mucosa in the esophagus is disclosed, such that the depth of the treated tissue is controlled. The depth of ablation is controlled by monitoring the tissue impedance and/or the tissue temperature. A desired ablation depth is also achieved by controlling the energy density or power density, and the amountof time required for energy delivery. A method and apparatus is disclosed for measuring an inner diameter of a body lumen, where a balloon is inflated inside the body lumen at a fixed pressure.

Description

METHODS AND SYSTEMS FOR DETERMINING PHYSIOLOGICAL CHARACTERISTICS FOR THE TREATMENT OF ESOPHAGUS FIELD OF THE INVENTION The present invention relates generally to medical methods and systems. More particularly, the invention is directed to methods and systems for treating and determining the physiological characteristics of body lumens such as the esophagus. BACKGROUND OF THE INVENTION The human body has a number of internal body lumens or cavities located within the body, many of which have a coating or inner layer. These internal coatings may be susceptible to diseases. In some cases, surgical intervention may be required to remove the internal lining in order to prevent the spread of the disease to other, otherwise healthy, tissue located nearby. Those with persistent problems of inappropriate relaxation of the inner esophageal sphincter may develop a condition known as gastroesophageal reflux disease, manifested by classic symptoms of heartburn and regurgitation of gastric and intestinal contents. The causative agent for such problems may vary, patients with severe forms of reflux disease REF. : 191773 gastroesophageal, no matter what the cause, can sometimes develop secondary damage of the esophagus due to the interaction of gastric or intestinal contents with esophageal cells not designed to experience such interaction. The esophagus is composed of three primary tissue layers; a superficial ucosal layer covered by squamous epithelial cells, an intermediate submucosal layer and a deeper muscular layer. When gastroesophageal reflux occurs, superficial squamous epithelial cells are exposed to gastric acid, along with intestinal bile acids and enzymes. This exposure can be tolerated, but in some cases it can lead to damage and alteration of the squamous cells, causing them to switch to larger, specialized, columnar epithelial cells. This metaplastic change of the mucosal epithelium from squamous cells to columnar cells is called Barrett's esophagus, named in honor of the British surgeon who originally described the condition. Barrett's esophagus has important clinical consequences, since Barrett's columnar cells can, in some patients, become dysplastic and then progress to a certain type of fatal cancer of the esophagus. The presence of Barret's esophagus is the main risk factor for the development of adenocarcinoma of the esophagus.

Consequently, attention has been focused on the identification and elimination of this abnormal Barrett columnar epithelium, in order to mitigate more severe implications for the patient. Devices and methods for treating abnormal body tissue by application of various forms of energy to such tissue have been described, such as radiofrequency ablation. However, without precise control of the penetration depth of the energy media, these methods and devices are deficient. The uncontrolled application of energy can penetrate too deeply into the esophageal wall, beyond the mucosal and submucosal layers, into the external muscle, potentially causing perforation of the esophagus, or bleeding from the esophagus. Consequently, proper administration of the correct amount of treatment energy to the tissue can be facilitated by knowledge of the size of the esophagus and the area to be treated. In addition, medical procedures to treat Barrett's esophagus typically involve the deployment of an expandable catheter into the esophagus. Expandable catheters are preferred because the catheter profile is ideally as small as possible to allow for ease of distribution, while the treatment of the esophagus is most efficiently performed when the catheter is equal to or slightly larger than the diameter of the catheter. the esophageal wall Proper size adjustment and / or pressurization of the dispensing device is therefore desirable to prevent over-distension of the organ, which could result in danger to the organ, or sub-expansion of the catheter, which often results in incomplete treatment. Consequently, accurate and simple measurement of lumen size and control of catheter pressure on the surface of the lumen promotes proper coupling and distribution of energy to the luminal wall, so that a uniform and controlled depth of treatment can be administered In addition to calculating the luminal dimensions, the flexibility of the lumen can be determined by measuring the cross section of the lumen at two or more pressure values. Therefore, it would be advantageous to have methods and systems to accurately determine the size in vivo and optionally the flexibility of a body lumen such as the esophagus. In addition, it would be desirable to provide a method and system for treating the body lumen having determined its size once. At least one of these objects will be fulfilled by the present invention. U.S. Patent No. 5,275,169 describes apparatus and methods for determining the physiological characteristics of blood vessels. The device measures the diameter and flexibility of the blood vessel wall, and does not administer treatment. In addition, the method relies on the use of only an incompressible fluid to inflate a balloon into a blood vessel. Other patents of interest include 6,010,511; 6,039,701; and 6,551,310. BRIEF DESCRIPTION OF THE INVENTION The present invention comprises methods and systems for measuring the size of a body lumen, such as the esophagus. Methods and systems for treating the body lumen are also provided once the appropriate measurements have been made. Although the following description will focus on the modalities configured for the treatment of the esophagus, other modalities may be used to treat any other suitable lumen in the body. In particular, the methods and systems of the present invention can be used whenever precise measurement of a body lumen or even energy distribution is desired, to treat a controlled depth of tissue in a lumen or body cavity, especially where such Body structures may vary in size. Therefore, the following description is provided for exemplary purposes and should not be considered as limited to the scope of the invention. In general, in one aspect, the invention features a method for measuring an internal diameter of a body lumen that includes the insertion of a balloon into the body lumen; inflating the balloon within the body lumen using a nest of expansion; and the monitoring of a mass of the medium of expansion within the globe. The implementations of the invention may include one or more of the following characteristics. Monitoring the mass of the expansion medium can be done using a mass flow sensor. In addition, the expansion medium can be a gas or a liquid, the balloon can be inflated to a fixed pressure, and the fixed pressure can be approximately 0.28 kg / cm2 (4 psig). In general, in yet another aspect, the invention features a method for treating tissue in a body lumen, including deployment of a selected electrode structure, on the tissue surface; the distribution of energy to the electrode structure to ablate or abrade the tissue at a depth from the surface; and the control of tissue depth eroded by monitoring a change in tissue impedance. Eroded tissue depth control can include monitoring when the tissue impedance reaches a target impedance value. In one implementation, the target impedance values are in ranges of approximately 0.5 ohms to 10 ohms. In yet another implementation, the control of the depth of eroded tissue may additionally include monitoring when the impedance of the tissue changes a specified percentage from an initial tissue impedance level. In a further implementation, the control of the eroded tissue depth may include monitoring when the impedance of the tissue reaches its minimum value. In a particular implementation, the desired depth of eroded tissue is approximately between 0.5 mm and 1 mm. In general, in yet another aspect, the invention features a method for treating the tissue of a body lumen, including: deploying an electrode structure on a tissue surface; the distribution of energy to the electrode structure to erode the tissue to a depth from the surface; and controlling the depth of tissue erosion by monitoring a change in tissue temperature. In one embodiment of this aspect of the invention, control of the depth of tissue ablation or erosion includes monitoring when the tissue temperature reaches a target range. The target temperature range can be between approximately 652 and 952C and the energy can be distributed as long as the measured tissue temperature does not exceed a maximum temperature. In one implementation, the maximum temperature is approximately 95eC. In general, in yet another aspect, the invention features a method for treating abnormal tissue within a body lumen, including: automatically determining an internal diameter of the body lumen at a site close to the abnormal tissue; deploying an electrode structure on a tissue surface at the proximal site; and distributing the energy to the electrode structure to treat the tissue. In one embodiment of this aspect of the invention, the internal diameter of the body lumen can be determined by automatically inflating and deflating a balloon within the body lumen using a means of expansion. This modality may also include monitoring a mass of the expansion medium within the balloon and controlling a depth of the treated tissue. In one implementation, the control of the depth of the treated tissue includes the control of an amount of energy distributed to the tissue over time. In other implementations, the control of the depth of the treated tissue includes the normalization of the energy distributed to the tissue over time; and / or controlling the depth of the treated tissue by controlling an amount of energy distributed to the tissue, over time and / or controlling the depth of the treated tissue by controlling the density of distributed energy; and / or controlling the depth of the treated tissue by monitoring and controlling the tissue impedance, over time; and / or temperature control of the treated tissue by monitoring and controlling the tissue temperature, over time. The implementations of the invention may include one or more of the following characteristics. The control of an amount of energy distributed to the tissue by rapidly increasing the energy until it reaches an established target value and / or control of the amount of energy distributed through the use of an integral, proportional derivative controller. In general, in yet another aspect, the invention features an apparatus for treating a tissue within a body lumen that includes: an electrode structure adapted to be placed on a tissue surface within the body lumen, wherein the structure of the electrode is coupled to an expansion member; and a generator to produce and distribute energy to the electrode structure; wherein the generator is adapted to automatically inflate the expansion member within the body lumen and control the pressure within the expansion member during tissue treatment. The implementations of the invention may include one or more of the following characteristics. The expansion member may be a balloon attached to a catheter. The apparatus may further include a storage device for storing generating accessories. In one implementation, the storage device is an EEPROM. The apparatus may further include a pump for automatically inflating and deflating the expansion member. The generator of the apparatus can be adapted to determine an internal diameter of the body lumen using an inflatable balloon. In one implementation, the generator is adapted to control the amount of tissue energy distributed over time based on the measured diameter of the esophagus. In yet another implementation, the generator is adapted to normalize the density of energy distributed to the tissue, based on the measured diameter of the esophagus. In yet another implementation, the generator is adapted to control the amount of tissue energy distributed over time, based on the measured diameter of the esophagus. In yet another implementation, the generator is adapted to control the energy distributed to the electrode structure. In a further implementation, the generator is adapted to control the energy distributed to the electrode structure. In yet another implementation, the generator is adapted to normalize the amount of energy distributed to the tissue, over time, based on the measured diameter of the esophagus. In a further implementation, the generator is adapted to detect whether or not a catheter is coupled to it, and to identify a feature of the coupled catheter. In a related implementation, the apparatus may further include a storage device adapted to store the information regarding the coupled catheter. The apparatus may further include a foot switch coupled to the generator and adapted to control the energy distributed to the electrode structure and / or a screen to display the information to a user. In yet another implementation, the generator is adapted to be manually controlled by a user, such that the user controls the energy distributed to the electrode structure, over time. The apparatus may further include an integral, proportional derivative controller, adapted to gradually increase the energy distributed to the electrode structure, until it reaches an established target value. In general, in yet another aspect, the invention features an apparatus for treating a tissue within a body lumen that includes: an electrode structure adapted to be placed on a tissue surface within the body lumen, wherein the electrode structure is coupled to an expansion member; and a generator for producing, distributing, and controlling the energy distributed to the electrode structure; wherein the generator is adapted to determine an internal diameter of the body lumen. In one aspect of the invention, a method for treating a body lumen at a treatment site comprises measuring a luminal dimension at the lumen treatment site, selecting an electrode deployment device having an array of electrodes or other electrode structure with an unfolded, preselected size, corresponding to the measured dimension, placing the electrode deployment device in the treatment site within the lumen, deploying the electrode array to the deployed, pre-selected state, to be coupled to a lumen wall, and distribute energy to the electrodes for the treatment of luminal tissue. In some embodiments, the measurement of the luminal dimension comprises placing a size determining member at the treatment site within the lumen, expanding the measurement member until it is coupled to an internal wall of the lumen, and calculating the Luminal dimension at the treatment site of the esophagus based on the expansion of the measurement member. Often, the expansion of the measurement member comprises the inflation of a size determination balloon, by the introduction of an expansion means. The expansion medium can be a compressible or non-compressible fluid. In some embodiments, the dimensions of the lumen are calculated by determining the amount of the expansion medium introduced into the size determination balloon while it is inflated. For example, the mass or volume of the expansion medium can be measured by the use of a mass flow meter or the like. Optionally, a pressure sensor can be coupled to the size determining balloon, so that the luminal dimension can be calculated from the measured amount of the expansion medium introduced to the balloon at a given pressure. Alternatively, the measurement member may comprise a basket, a plurality of posts or gauges, or the like. The lumen can also be measured by ultrasound, by optical or fluoroscopic image formation, or by the use of a measuring strip. In embodiments where a size measurement balloon is employed, the measurement balloon may comprise any configuration material. In general, the measuring balloon is cylindrical and has a known length and a diameter that is larger than the diameter of the target lumen. In this configuration, the measuring balloon is non-distensible, such as a bladder having a diameter in its fully expanded form that is greater than the diameter of the lumen. Suitable materials for the balloon may comprise a polymer such as a polyimide or polyethylene terephthalate (PET). Alternatively, the balloon may comprise a mixture of polymers and elastomers. Once the dimensions of the lumen are determined, an electrode deployment device that matches the luminal dimension measured from an inventory of devices having different electrode deployment sizes can be selected. In some embodiments, the electrode deployment device is trans-esophageally distributed to a treatment area within the esophagus. For example, the distribution of the device can be facilitated by the advancement of a catheter through the esophagus, wherein the catheter carries the electrode array and an expansion member. The expansion member may comprise any of the materials or configurations of the measurement member, such as an inflatable cylindrical balloon comprising a polymer such as polyimide or PET. In some aspects of the invention, the array of electrodes or other electrode structure is accommodated on a surface of a dimensionally stable support such as an electrode backing., not distensible. The backing may comprise a thin rectangular sheet of polymeric materials such as polyimide, polyester or other flexible thermoplastic or a thermosetting polymeric film, materials coated with polymer and other non-conductive materials. The backing may also comprise an electrically insulating polymer, with an electroconductive material, such as copper, deposited on a surface. For example, an electrode pattern can be etched into the material to create an array of electrodes. The electrode pattern can be aligned in an axial or transverse direction, through the backrest, formed in a linear or non-linear parallel array or a series of bipolar pairs, or another suitable pattern. In many modalities, the energy distribution comprises the application of radiofrequency energy (RF) to the tissue of the body lumen, through the electrodes. Depending on the effect of the desired treatment, the electrodes may be arranged to control the depth and pattern of treatment. For the treatment of the esophageal tissue, the electrode widths are less than 3 mm, typically a width in the range of 0.1 to 3 mm, preferably 0.1 mm to 0.3 mm, and the adjacent electrodes are spaced less than 3 mm, typically in the range from 0.1 mm to 3 mm, preferably from 0.1 mm to 0.3 mm. Alternatively, energy can be distributed through the use of structures different from those that have an array of electrodes. For example, the electrode structure may comprise a continuous electrode accommodated in a helical pattern on the balloon. In yet another method of the present invention, the measurement of the luminal dimension can be used to determine the amount of energy distributed to the lumen tissue. For example, a method for treating the tissue of a body lumen at a treatment site comprises the measurement of a luminal dimension at a lumen site, the placement of an electrode deployment device at that site, the deployment of the expansion member. for coupling an electrode array to a lumen wall, and distributing sufficient energy to the electrode array for treatment of luminal tissue based on the measured dimension of the lumen. In general, the amount of energy distributed to the electrodes will vary depending on the type of treatment and the entire surface area of the luminal tissue to be treated. In some embodiments, the expansion member can be variably expanded to engage the wall of the lumen, regardless of the size of the lumen. For the treatment of the esophagus, the expansion member may comprise a balloon that can be expanded to a range of diameters between 12 mm and 50 mm. Typically, the total energy density distributed to the esophageal tissue will be in the range of 1 J / cm to 50 J / cm, usually from 5 J / cm2 to 15 J / cm2. In order to effectively erode the mucosal lining of the esophagus and allow the re-growth of a normal mucosal lining without creating damage to the underlying tissue structures, it is preferable to distribute radiofrequency energy in a short time, in order to reduce the effects from the thermal conduction of the energy to deeper titling layers, with which a "cauterization" effect is created. It is preferable to distribute the radiofrequency energy within a time period of less than 5 seconds. An optimum time for effective treatment is less than 1 second and preferably less than 0.5 seconds or 0.25 seconds. The lower limit on time may be limited by the ability of the RF energy source to distribute high energies. In one aspect of the invention, a method for measuring an internal dimension at a site in a body lumen, comprises placing a cylindrical balloon at a site within the lumen, inflating the balloon with an expansion means to be coupled to an inner wall of the lumen, monitoring the degree of balloon coupling, determining the amount of expansion medium in the balloon while inflating at the site, and calculating the internal dimension of the esophagus based on the length of the balloon and the amount measured of the medium of expansion within the globe. In some modalities, the balloon is transesophageally distributed to a treatment area within the esophagus, by the advancement of a catheter that carries the balloon through the esophagus. Often, the balloon is non-distensible and has a diameter that is greater than the diameter of the internal wall of the lumen. The balloon can be filled with an expansion medium that is a compressible fluid, such as air. The monitoring of the coupling degree comprises the determination of the expansion of the balloon via a pressure sensor connected to the balloon, where the degree of coupling is determined by the internal pressure exerted from the expansion medium, as measured by the pressure sensor and by visual verification. The pressure sensor may comprise any device for determining the pressure within a vessel, such as a strain gauge. Alternatively, the degree of coupling can be monitored by the determination of balloon expansion via visual inspection. In some embodiments, the balloon may be expanded to apply pressure to the inner wall of the lumen, thereby causing the lumen to stretch. In one aspect of the invention, a method for determining the flexibility of the wall of an esophagus, comprises placing a balloon at a site within the esophagus, inflating the balloon with a compressible fluid, measuring the static pressure inside the balloon, measuring the total amount of fluid within the balloon at least two values of static pressure and calculating the flexibility of the wall based on the variation in the amount of fluid between a first measured pressure and a second measured pressure. For esophageal treatment, the static pressure values to be used are typically below 0.70 kg / cm2 (10 psig), and preferably at or below 0.49 kg / cm2 (7 psig). In yet another aspect, a system for treating the tissue of a body lumen comprises a measurement member for measuring the cross section at a lumen site and a catheter having a group of individual treatment devices, each device comprising an electrode array adapted to treat a target site, wherein at least some of the arrangements are adapted to handle sites having different sizes, determined by the measurement member. In some embodiments, the metering member comprises a non-flexible, inflatable metering balloon that is larger in size with respect to the inner wall of the lumen. The measuring balloon may be cylindrical with a diameter that is larger than the inner wall of the lumen. The measuring balloon can also be coupled to a pressure sensor to determine the internal pressure of the balloon from the introduction of the expansion medium. In addition, the system may comprise a measuring means, such as a mass flow meter, for determining the amount of fluid in the measuring balloon. In some embodiments, each of the individual treatment devices further includes an expansion member and an inflatable balloon. In general, each balloon is cylindrical and is in the range of diameter from 12 mm to 50 mm when expanded. A balloon within the range is selected based on the measurement made from the measurement balloon, so that when the balloon is expanded to its fully inflated shape, it appropriately couples to the wall of the lumen. Typically, the expansion member is inflated with the same medium as the measuring balloon. Optionally, the treatment device may further include a pressure sensor as an extra precaution against over-distension of the organ. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic view of the portions of a superior digestive tract in a human. Figure 2 is a cross-sectional view of a device of the invention inserted into an esophagus in its relaxed collapsed state. Figure 3 is a cross-sectional view of a device of the invention deployed in an expanded configuration in the esophagus. Figure 4 is a schematic view of a measuring device of the invention. Figure 5 is a flow chart of a method of the invention for measuring a luminal dimension. Figure 6 is a flow diagram of a method of the invention for treating a luminal tissue. Figure 7 is a diagram of the test results performed when calculating the diameter of a vessel by measuring the volume of air used to inflate the balloon. Figure 8 is a diagram of the test results for the air mass required to achieve various pressure levels in rigid containers of different size. Figure 9 is a schematic view of a treatment device of the invention in a configuration compressed in the esophagus. Figure 10 is a schematic view of a treatment device of the invention in an expanded configuration in the esophagus. Figure 11 is a schematic view of yet another embodiment of the treatment device of the invention. Figure 12 shows a top view and a bottom view of an electrode pattern of the device of Figure 11. Figures 13a-13c show the electrode patterns that can be used with a treatment device of the invention. Figures 14a-14d show the additional electrode patterns that can be used with a treatment device of the invention. Figure 15 shows a flow chart of a method of the invention for determining the flexibility of a lumen wall. Figure 16 illustrates a flow chart of a method for estimating size. Figure 17 illustrates an exemplary scheme of a mechanism for performing balloon measurement using a mass flow meter and pressure sensors. Figure 18 is an exemplary flow chart of the ablation or erosion method. Figure 19 illustrates a graphical representation of tissue impedance over time. Figure 20 illustrates a graphical representation of tissue temperature over time. Figure 21 illustrates an exemplary front panel of the generator. All publications and patent applications mentioned in this specification are incorporated herein by reference to the same degree as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. DETAILED DESCRIPTION OF THE INVENTION In various modalities, the present invention provides methods and systems for measuring, and for treating at a controlled and uniform depth, the inner lining of a lumen within a patient. It will be appreciated that the present invention is applicable to a variety of different titular sites and organs, including but not limited to the esophagus. A treatment apparatus is provided that includes a size measurement member and a treatment device comprising an expandable electrode array. The size measurement member is first placed in a treatment site within the lumen. Once in place, the measurement member is expanded to attach to the wall of the lumen to obtain lumen dimensions. The measurement member is removed, and at least a portion of the treatment device is placed at the site of the tissue, where the expanded electrode arrangement makes contact with the tissue surface according to measurements made by the measurement member. Sufficient energy is then distributed from the electrode array to impart a desired therapeutic effect, such as cell necrosis to a discrete layer of the tissue. Certain disorders may cause the retrograde flow of gastric or intestinal contents from the stomach 12 into the esophagus 14, as shown by arrows A and B in Figure 1. Although the causes of these problems are varied, these retrograde flows may give as a result secondary disorders, such as the Barrett's esophagus, that require independent treatment of and very different from appropriate treatments for the primary disorder, such as disorders of the lower esophageal sphincter 16. Barrett's esophagus is an inflammatory disorder in which Stomach acids, bile acids and regurgitated enzymes from the stomach and duodenum enter the inner esophagus, causing damage to the esophageal mucosa. When the type of retrograde flow occurs frequently, damage to the esophageal epithelial cells can occur. In some cases, the damage can lead to the alteration of the squamous cells, causing them to change to higher specialized, columnar epithelial cells. This metaplastic change of the mucosal epithelium from squamous cells to columnar cells is called Barret's esophagus. Although some of the columnar cells may be benign, others may result in adenocarcinoma. In one aspect, the present invention provides methods and systems for measuring the size of the esophagus and treating the epithelium of selected sites of the esophagus in order to mitigate the most severe implications for the patient. In many therapeutic procedures according to the present invention, the desired treatment effect is tissue ablation or erosion. The tissue "ablation or erosion" as used herein, means the thermal damage to tissue that causes tissue or cell necrosis. However, some therapeutic procedures can have a desired treatment effect that does not reach ablation or erosion, for example, some level of agitation or damage that is imparted to the tissue to result in a desired change in the cellular constitution of the tissue instead of tissue. of tissue necrosis. With the present invention, a variety of different energy distribution devices can be used to create a treatment effect on a surface layer of tissue, while the function of the deeper layers is preserved intact, as described below in FIG. I presented. Tissue cell necrosis can be achieved with the use of energy, such as radiofrequency energy, at appropriate levels to achieve tissue ablation at the mucosal or submucosal level, while substantially preserving muscle tissue. In a particular aspect, such ablation is designed to eliminate the complete mucosal lining in the treatment region, including abnormal columnar growths 20 from the portions of esophagus 14 thus affected, and allowing the regrowth of a normal mucosal lining. As illustrated in a cross-sectional view in Figure 2, the esophagus in its relaxed, folded state does not form a perfect cylindrical tube. Rather the walls of the esophagus 14 are undulated in a plurality of folds. In this state, the diameter of the esophagus is difficult to determine, especially by the use of visualization techniques such as ultrasound or optical imaging. In addition, the uniform treatment of target tissue areas is also difficult due to the superficial and regular contours of the esophageal wall. In one embodiment of the invention, as illustrated in Figures 2, 3 and 4 and the flow chart of Figure 5, a method is described for using a size measuring device for measuring luminal dimensions. The measuring device 40 is first distributed to the treatment region in the body lumen, as shown in block 70. For the measurement of the size of the esophagus as shown in Figure 2, the esophagus 14 will be in a relaxed configuration or folded during the distribution of the measuring device. The measuring device 40 is in a folded configuration during the distribution of the device to the treatment site in the esophagus. The low profile of the folded measuring device 40, as shown in Figure 2, facilitates the distribution of the device towards the esophagus and minimizes discomfort to the patient. Once the measurement device is oriented in the appropriate treatment area, an expansion fluid is injected into the balloon, as shown in block 72. The balloon is inflated until it occupies the inner wall of the lumen, as shown in FIG. shown in Figure 3. During the infusion of the expansion medium, the degree of coupling of the balloon is monitored, as well as the amount of expansion medium that is injected into the balloon, as shown by block 74. Once the balloon is suitably coupled to the wall of the lumen (shown in block 76), the mass or final volume of the expansion medium is recorded, so that the internal dimension of the esophagus can be calculated, shown in blocks 78, 82. The measuring balloon is then deflated so that it can be easily removed from the treatment site, shown in block 80. With reference to FIGS. 2, 3, 4, a device of the present invention comprises a device 40. of size measurement to determine the dimensions of a treatment lumen. The device 40 has an expansion number 42 that is inserted into a lumen in a collapsed or collapsed configuration, and expanded after proper placement in a preselected treatment area. In a preferred configuration, the expansion member 42 is a cylindrical balloon with a native diameter that is larger in size, so that it may be larger in its fully expanded configuration than the expected diameter of the treatment lumen. The balloon 42 comprises a flexible, thin bladder made of a polymeric material, for example polyimide, polyurethane, PET or the like. The balloon is coupled to a catheter sleeve 44, wherein the balloon is placed over the distal end 46 of the catheter sleeve for infusion of an expansion medium into the balloon of an IS infusion source. The infusion source is connected to an access gate 50 of a connector Y located at the proximal end 48 of the catheter sleeve 44. Ideally, the expansion means comprises a compressible fluid, such as air. The expansion means may alternatively comprise an incompressible fluid, such as water, saline or the like. It could be understood by a person of ordinary skill in the art that measuring the size of a body lumen by monitoring the mass of an expansion medium, it can be advantageously achieved using fluids either compressible or incompressible. The infusion of the expansion medium into the balloon of size measurement can be achieved by a positive displacement device such as a fluid infusion pump or a calibrated syringe driven by a gradual or manually moving motor. Alternatively, for a compressible expansion medium, pressurized air or gas can also be used. In many embodiments, the size measuring device also comprises a means for determining the amount of expansion fluid transferred to the balloon, such as a calibrated syringe. A mass or volume flow meter may also be coupled to the fluid distribution source to simultaneously measure the amount of fluid in the balloon as it is inflated. As the expansion means is injected into the balloon 42, the balloon expands radially from its axis to engage the wall of the lumen. For esophageal treatment, the walls of the esophagus 14 unfold to form a more cylindrical shape as the balloon 42 expands, as illustrated in Figure 3. In this configuration, the internal diameter DI of the esophagus 14 is easily calculated based on the length L of the balloon and the measured amount of the expansion medium within the balloon. The balloon 42 is larger in size, so that the diameter D2 of the balloon when it is not restricted and fully inflated is larger than the diameter of the balloon when it is constricted in the lumen. Although an inflatable balloon is generally preferred, the size measurement member may comprise a basket, a plurality of posts, callipers or similar instruments for determining the internal diameter of a tubular member. Tests were performed to calculate the internal diameter of a limb by using volumetric flow measurements. Various types and sizes of tubes were tested by measuring the mass of air used to inflate a larger bladder, inside the tube. As shown in Figure 7, the diameter of the tube can be repeatedly estimated by measuring the volume of air distributed to the balloon. In some embodiments of the invention, a pressure sensor may be coupled to the size measuring device, wherein the degree of coupling is determined by the internal pressure exerted from the expansion means as measured by the pressure sensor or the verification visual. The pressure sensor can comprise any device for determining the pressure inside a container, such as a voltage meter. In Figure 4, the pressure sensor PS is located in the access gate 52 at the proximal end of the catheter sleeve 44. Alternatively, the pressure sensor may be located within the balloon 42. As the balloon expands to engage the wall of the lumen, the pressure in the balloon increases as a result of constriction on the balloon from the wall of the lumen.

Because the balloon is larger in size and is not at its fully extended diameter when it contacts the wall of the lumen, the pressure in the balloon equals the contact force per unit of air against the wall of the lumen. Therefore, the pressure inside the balloon is directly proportional to the contact force on the wall of the lumen. In addition, the balloon can be expanded to apply pressure to the inner wall of the lumen, thereby causing the lumen to stretch. In general, the measuring balloon will be inflated to a pressure corresponding to the pressure desired for the treatment of the lumen. For esophageal treatment, it is desirable to expand the treatment device sufficiently to occlude the vasculature of the submucosa, including the arterial, capillary or venular vessels. The pressure that is to be exerted must therefore be greater than the pressure exerted by such vessels, typically from 0.07 kg / cm2 (1 psig) to 0.7 kg / cm2 (10 psig), preferably 0.28 kg / cm2 (4 psig) to 0.49 kg / cm2 (7 psig) and more preferably from 0.14 kg / cm2 (2 psig) to 0.21 kg / cm2 (3 psig). In some modalities, the pressure measurement inside the balloon can be used to monitor the degree of coupling of the balloon with the wall of the lumen. Alternatively, the degree of coupling can be monitored by determining balloon expansion via visual expansion with the use of an endoscope, or by ultrasound, optical or fluoroscopic imaging (not shown). Tests were carried out on rigid tubes of different sizes to calculate the amount of mass required to inflate a balloon of larger size in a constricted tube, at various pressures. As shown in Figure 8, the test results showed predictable linear relationships between the mass of the inflated, measured air, and the diameter of the tube for each tested pressure range. As shown in the flow diagram of Figure 6, a method and system of the present invention is described for treating a luminal tissue. Similar to the method described in Figure 5, a size measuring device is used to calculate the internal diameter of the lumen, as shown in block 84. The measurement obtained from the measuring device is then used to select a device for measuring the internal diameter of the lumen. treatment of an array of catheters of different sizes, shown in block 86. The device is then inserted into the lumen of the body and distributed to the treatment site, as shown in block 88. An expansion fluid is then injected into the device by an infusion source such as that of the measuring device as shown in block 90. Because the catheter is selected to have an external diameter when it is fully expanded, which properly distends the luminal wall, it is not necessary to monitor the expansion of the catheter. However, the pressure and fluid volume of the expansion medium distributed to the treatment device can be monitored as a precautionary measure, as shown in blocks 92 and 94. With the catheter suitably coupled to the luminal wall at the site of treatment, the energy, such as RF energy, is distributed to the catheter for the treatment of the luminal tissue, as shown in block 96. Once the treatment has been administered, the catheter is deflated for lumen removal as described. shown in block 98. As illustrated in FIGS. 9 and 10, a treatment device 10 constructed in accordance with the principles of the present invention, includes an elongated catheter sleeve 22 that is configured to be inserted into the body in either of the various forms selected by the medical provider. For the treatment of the esophagus, the treatment device can be placed, (i) endoscopically, for example through the esophagus 14, (ii) surgically, or (iii) through other means. When an endoscope (not shown) is used, the sleeve 22 of the catheter can be inserted into the lumen of the endoscope, or the sleeve 22 of the catheter can be placed on the outside of the endoscope. Alternatively, an endoscope may be used to visualize the guide that catheter 22 must follow during placement. Also, the sleeve 22 of the catheter can be inserted into the esophagus 1014 after removal of the endoscope. An electrode holder 24 is provided and can be placed at a distal end 26 of the catheter sleeve 22 to provide the appropriate energy for ablation, as desired. The electrode holder 24 has a plurality of segments 32 of electrode area coupled to the surface of the support. The electrodes 32 can be configured in an array 30 of different patterns to facilitate specific treatment by controlling the size of the electrode and the spacing thereof (electrode density). In various embodiments, the electrode holder 24 is coupled to a power source configured to energize the array 30 at appropriate levels to provide selectable tissue ablation at a predetermined depth of tissue. The energy can be distributed circumferentially around the axis of the treatment device in a simple step, for example, all at once. Alternatively, the energy can be distributed to circumferential and / or axial sections different from the esophageal wall, sequentially. In many embodiments, the support 24 may comprise a flexible, non-distensible backing. For example, the support 24 may comprise a thin rectangular sheet or sheet of polymeric materials such as polyimide, polyester or other flexible thermoplastic or thermosetting polymeric film. The support 24 may also comprise materials covered with polymer, or other non-conductive materials. In addition, the backing can include an electrically insulating polymer, with an electroconductive material, such as copper, deposited on a surface, so that an electrode pattern can be etched into the material to create an array of electrodes. The electrode holder 24 can be operated at a controlled distance from, or in direct contact with the wall of the tissue site. This can be achieved by coupling the electrode holder 24 to an expandable member 28, which has a cylindrical configuration with a fixed, known length, and a diameter of adequate size to correspond in its expanded state to the calculated diameter of the expanded lumen ( not folded or collapsed). Suitable expandable numbers include, but are not limited to, a balloon, a non-flexible balloon, a balloon with a tapered geometry, a cage, structure, basket, plurality of poles, expandable member with a rolled state or an unwound state, one or more springs or springs, foam, bladders, backing material that expands to an expanded configuration when not restricted, and the like. For esophageal treatment, it is desirable to expand the expandable member to distend the lumen sufficiently to occlude the vasculature of the submucosa, including the arterial, capillary or venular vessels. The pressure that is to be exerted should therefore not be greater than the pressure exerted by such vessels, typically from 0.07 kg / cm2 to 0.70 kg / cm2 (1 psig to 10 psig), preferably from 0.28 kg / cm2 to 0.49 kg / cm2 (4 psig to 7 psig) and more preferably from 0.14 kg / cm2 to 0.21 kg / cm2 (2 psig to 3 psig). In general, the expandable member for the treatment device will be selected to correspond to or adjust to the diameter measured by the measuring device at the desired pressure. Under this configuration, the complete expansion of the expandable member will result in a pressure that adequately distends the luminal wall. In some modalities, it may be desirable to employ a pressure sensor or mass flow meter (not shown), as a precautionary measure so that over-distension of the lumen does not occur. As shown in Figures 9 and 10, the electrode holder 24 is wrapped around the circumference of the expandable member 28. In a system of the present invention, a plurality of expandable members can be provided, wherein the diameter of the expandable member it varies from 12 mm to 50 mm when it is expanded. Accordingly, the system can include a plurality of electrode holders, each of different size corresponding to the expandable members of different sizes. Alternatively, the electrode holder 24 may be larger in size to be at least large enough to cover the circumference of the larger expandable member. In such a configuration, the electrode holder overlaps itself as it is wrapped around the circumference of the expandable member, similarly to the electrode holder of the device 100 illustrated in '1, discussed above. In yet another embodiment, the expandable member 28 is used to distribute the ablation energy itself. An important feature of this embodiment includes the means by which energy is transferred from the distal end 26 to the expandable member 28. By way of illustration, one type of energy distribution that can be used is described in the United States Patent. No. 5,713,942, incorporated by reference herein, in which an expandable balloon is connected to an energy source, which provides radiofrequency energy having the desired characteristics to selectively heat the target tissue to a desired temperature. Expandable member 28 can be constructed of electrically insulating polymer, with an electroconductive material, such as copper, deposited on a surface, so that an electrode pattern can be etched into the material to create an array of electrodes. The electrode holder 24 can distribute a variety of different types of energy, including but not limited to, radiofrequency, microwave, ultrasonic energy, resistive heating, chemical energy, a heatable fluid, optical energy including without limitation, ultraviolet light, visible, infrared. , collimated or non-collimated light, coherent or non-coherent light or other luminous energy, and the like. It will be appreciated that energy, including but not limited to optical energy, can be used in combination with one or more sensitizing agents. The depth of the treatment obtained with the treatment device 10 can be controlled by the selection of the appropriate treatment parameters by the user, as described in the examples described herein. An important parameter in the control of the treatment depth is the density of the arrangement 30. Since the spacing between the electrodes decreases, the treatment depth of the affected tissue also decreases. The very close spacing of the electrodes ensures that the current and the resulting ohmic heating in the tissue is limited to a very low depth so that damage and heating of the mucosal layer is minimized. For the treatment of esophageal tissue using radiofrequency energy, it may be desirable to have a width of each RF electrode no greater than, (i) 3 mm, (ii) 2 mm, (iii) 1 mm (iv) 0.5 mm or ( v) 0.3 mm (vi) 0.1 mm and the like. Accordingly, it may be desirable to have a spacing between the adjacent RF electrodes not greater than (i) 3 mm, (ii) 2 mm, (iii) 1 mm (iv) 0.5 mm or (v) 0.3 mm (vi) 0.1 mm and similar. The plurality of electrodes can be accommodated in segments, with at least a portion of the segments that are multiplexed. An RF electrode between adjacent segments can be shared by each of the adjacent segments when multiplexed. The electrode patterns of the present invention can be varied depending on the length of the site to be treated, the depth of the mucosa and the submucosa, in the case of the esophagus, in the treatment site and other factors. The electrode pattern 30 may be aligned in the axial or transverse direction through the electrode holder 24, or formed in a linear or non-linear parallel array, or a series of bipolar pairs or monopolar electrodes. One or more different patterns may be coupled to various sites of the expandable member 28. For example, an array of the electrode, as illustrated in Figures 13 (a) to 13 (c), may comprise a pattern of finger electrodes 68. intercalated axial, bipolar, six bipolar rings 62 with 2 mm separation, or monopolar rectangles 65 with 1 mm separation. Other suitable RF electrode patterns that may be used include, without limitation, those patterns shown in Figures 14 (a) through 14 (d) as 54, 56, 58 and 60, respectively. Pattern 54 is a pattern of intercalated, axial, bipolar finger electrodes with 0.3 mm spacing. Pattern 56 includes monopolar strips with a 0.3 mm spacing. Pattern 60 includes bipolar rings with 0.3 mm spacing. The pattern 58 is the electrodes in a wavy electrode pattern with a 0.2548 mm spacing. A probe sensor may also be used with the system of the present invention to monitor and determine the depth of ablation or erosion. In one embodiment, one or more sensors (not shown), including but not limited to thermal and the like, may be included and associated with each electrode segment 32 in order to monitor the temperature of each segment and then be used for control . The control can be by means of an open or closed circuit feedback system. In yet another embodiment, the electroconductive member may be configured to allow the transmission of microwave energy to the tissue site. The treatment apparatus 10 may also include directional and directional control devices, a probe sensor for accurately detecting the depth of ablation and the like. With reference to Figure 11, one embodiment of the invention comprises an electrode deployment device 100 having an electrode holder 110 wound around the outside of an inflatable balloon 116 that is mounted on a sleeve 118 of the catheter. The support 110 has an electrode array 112 etched onto its surface, and is aligned between the edges 120 intersecting the tapered region located at the distal and proximal ends of the balloon 116. The support 110 may be coupled at a first end 122. to balloon 116 with an adhesive. The second end 124 of the support is wound around the balloon, overlapping the first end 122. Alternatively, the support 110 can be retained in a rolled state, compressed around the balloon 116 by an elastic band. In such a configuration, adhesive need not be applied to couple the first end 122 to the balloon 116, thereby allowing rapid placement or exchange of the balloon 116 of appropriate size to correspond to the measurements made from the measuring device 10 illustrated in FIG. Figure 4. Figure 12 shows a bottom view 150 and a top view 152 of the electrode array 112 of the support 110. In this embodiment, the array 112 has 20 parallel bars, 0.25 mm wide, separated by empty spaces of 0.3 mm . The bars on the circuit form complete continuous rings around the circumference of the balloon 116. The electrode array 112 can be etched from a laminate consisting of copper on both sides of a polyimide substrate. One end of each copper bar has a small, plated side-by-side hole 128 that allows signals to be passed to these bars from 1 of 2 copper junction blocks 156 and 158, respectively, on the back of the bar. laminate. A link block 156 is connected to all the even number bars, while the other link block 158 is connected to all odd number bars. As shown in Figures 11 and 12, each junction block 156 and 158 is then wired to a bundle of AWG wires 134. The wiring is external to balloon 116, with wires or wires from the distal circuit fixed below the proximal circuit. After encountering the catheter sleeve of the device, these bundles 134 can be welded to three bundles of litz cable 136. One bundle 136 serves as a common conductor for both circuits, while the other two bundles 136 are individually wired to each of the two circuits. The litz cables are encompassed with heat shrink tubing along the entire length of the catheter sleeve 118, of the device. After emerging from the proximal end of the catheter sleeve, each of these bundles 136 is individually insulated with the heat shrink tubing, before terminating to a plug 138 mini connector. Under this configuration, the energy can be distributed to one or both of the two bundles, so that the treatment can be administered to a specific area throughout the array. The connector and 142 at the proximal end of the catheter sleeve includes the access gates for the side-to-side lumen 144 and the inflation lumen 146. The side-to-side lumen spans the entire length of the balloon catheter and exits at through tip 148 of the lumen at the distal end of balloon 116. Inflation lumen 146 is coupled to balloon 116, so that the balloon can be inflated by the distribution of a liquid, a gaseous solution such as air, or the like . In some embodiments, for the dispensing of the apparatus 100, the support 110 is tightly wound around the deflated balloon 116 and placed therewith within a sheath (not shown). During deployment, this sheath is retracted along the axis to expose the support 110. In alternative embodiments, an elastic member (not shown) may be coupled to the support 110 to keep the support wrapped around the balloon 116 during deployment of the apparatus. 100. In order to ensure good contact between the wall of the esophagus and the array 112 of the electrode, a slight suction may be applied to the lumen tube from side to side to reduce the air pressure in the esophagus 14 distal to the balloon 116 The application of this slight suction can be simultaneously applied to the portion of the esophagus 14 proximal to the balloon 116. This suction causes the portion of the wall of the esophagus distended by the balloon 116 to be pulled against the electrode arrays 112 located on the balloon 116. Apparatus 100, illustrated in Figure 11, is designed for use with RF energy methods as described herein. The electrode array 112 can be activated with approximately 300 watts of radio frequency energy for the length of time necessary to distribute an energy density of 1 J / cm2 at 50 J / cm2. To determine the appropriate level of energy, the diameter of the lumen is evaluated, so that the total treatment area can be calculated. A typical treatment area of 10 cm2 will require total energy in the range of 10 J to 500 J. In one embodiment, the control of the depth of the treated tissue may include normalization of the amount of energy distributed to the tissue, over time. In this context, the distributed normalization energy means that equivalent energy densities (eg, unit area of energy of the surface area of the electrode { W / cm2.}.) Are distributed to the esophagus of different diameters. In another embodiment, the control of the depth of the treated tissue comprises controlling the amount of distributed energy density. This can be achieved by normalizing the amount of energy distributed to the tissue over time, so that different equivalent energy densities (for example, energy per unit area of the surface area of the electrode. { J / cm2} ) are distributed to esophagus of different diameters. In order to effectively erode the mucosal lining of the esophagus and allow the regrowth of a normal mucosal lining without creating damage to the underlying tissue structure, it is preferable to distribute the radiofrequency energy in a short time, in order to reduce the effects of the thermal conduction of the energy to deeper tissue layers, creating with this a "cauterization" effect. It is preferable to distribute the radiofrequency energy within a time period of less than 5 seconds. An optimal time for effective treatment is less than 1 second and preferably less than 0.5 seconds or 0.25 seconds. The lower limit on time may be limited by the ability of the RF energy source to distribute higher energies, or alternatively by the depth of treatment required. Since the area of the electrode and consequently the tissue treatment area can be as much as several square centimeters, RF energies of several hundred watts could be required in order to distribute the desired energy density in short periods of time. weather. This can impose a practical limitation on the lower limit of time. However, an RF energy source configured to distribute a very short high-energy pulse could be used. Using techniques similar to those used for incandescent lamp sources, or other types of capacitor discharge sources, a very high energy short pulse of RF energy can be created. This could allow treatment times of a few milliseconds or less. While this type of procedure is feasible, in practice a more conventional RF source with an energy capacity of several hundred watts may be preferred. The power source can be manually controlled by the user and is adapted to allow the user to select the appropriate treatment time and energy setting to obtain a controlled depth of ablation or erosion. The power source may be coupled to a controller (not shown), which may be a digital or analog controller for use with the power source, including but not limited to an RF source, or a computer with software. When the computer's controller is used, it can include a central processing unit (CPU) connected through a bus or collective bar of the system. The system may include a keyboard, a disk drive, or other non-volatile memory system, a screen and other peripheral devices known in the art. A program memory and a data memory will also be connected to the collective bar. In some embodiments of the present invention, systems and methods for treating luminal tissue are described with a simple treatment device that is variably expanded to accommodate a number of lumens of different sizes. Preferably, the treatment device comprises a wound electrode support, which is variably coupled to the luminal wall while maintaining the density of the electrode constant. Such procedures are described in detail in copending application No. 10 / 754,444 (Attorney's Case No. 021827-0040US), the full disclosure of which is incorporated by reference herein. For example, for the treatment device 100 shown in Figure 11, which employs an array of electrode 112, of variable, exposed length, the balloon 116 may be larger in size with respect to the size of the lumen, so that it may be be expanded to accommodate different luminal dimensions from patient to patient. Measurements from the size measurement device 10 can be used to change the scale as necessary to the desired energy and power settings, to distribute the same power and energy per unit area. These changes can be made either automatically or from the user input to the RF power source. If different depths of treatment are desired, the geometry of the electrode array 112 can be modified to create a deeper or more shallow treatment region. Making the array electrodes 112 narrower and spacing the electrodes closer to each other reduces the depth of treatment. By making the array electrodes 112 wider, and by placing the electrodes further apart, the depth of the treatment region is increased. The non-uniform widths and spacings can be exploited to achieve various treatment effects. With reference to Figure 15, the size measurement device can be used as a method to determine the diameter of the lumen and the flexibility of the wall of one or more sections of the esophagus. A size measuring device having an inflatable balloon like that of the device 40 illustrated in Figure 5, is inserted into the esophagus in a compressed configuration and placed at a site within the esophagus, as shown in block 200. The balloon it is then inflated with a compressible fluid so that the balloon attaches to the inner wall of the esophagus and distends the wall of the esophagus, shown in block 202. While the expansion medium is distributed to the balloon, the static pressure within the balloon is monitored with a pressure sensor and the amount of expansion medium distributed to the balloon is measured, shown in block 204. The pressure can be measured at the infusion source with a strain gauge or the like. Alternatively, the pressure can be measured at a site within the balloon with a microminiature pressure transducer or the like. The amount of expansion medium distributed to the balloon can be measured by a mass flow meter or the like. Once a first objective pressure (Pl) is reached within the balloon, a corresponding first measurement of mass or volume (Ml) is recorded, as shown in blocks 206 and 208. The values of Pl and Ml are used to calculate the diameter of the lumen at the pressure Pl, using the previously determined relationship and shown in Figure 8, block 200 of Figure 15, or other equivalent means. The additional expansion medium is then distributed to the balloon, and the static pressure and the total amount of expansion medium within the balloon are monitored, shown in blocks 210 and 212. This continues until a second objective pressure (P2) is reached. within the balloon, and a corresponding second measurement of mass or volume (M2) is recorded, as shown in blocks 214 and 216. The calculation of the lumen diameter at pressure P2 is performed as previously described and shown in the block 220. The size measuring balloon is then deflated and then removed from the esophagus as shown in block 218. The objective pressure values Pl and P2 are generally adjusted to values that cause the esophagus to distend, but not over -Distienda. Typical target pressure values are in the range of 0.07 kg / cm2 (1 psig) to 0.49 kg / cm2 (7 psig), preferably 0.28 kg / cm2 (4 psig) to 0. 49 kg / cm2 (7 psig) and most preferably 0.14 kg / cm2 (2 psig) up to 0.21 kg / cm2 (3 psig). The flexibility of the esophageal wall is then determined based on the variation in the calculated diameter of the lumen, between a first measured pressure Pl and a second measured pressure P2, as shown in block 222. Figure 21 is a front panel exemplary of a generator system according to one embodiment of the invention. In one embodiment, generator 230 produces, distributes and controls energy, such as RF energy. Other functions of the generator 230 include controlling the inflating and deflating the size measuring balloon, estimating the size of the measuring balloon, the selective distribution of the energy and RF power to a treatment catheter, and the specific electrodes within the catheter. of treatment, and showing various information to the user. To distribute various information regarding the parameters of use and the state of the system, the front panel of the generator 230 incorporates various controls, screens and indicators. The generator 230 connects the catheter 22 through the RF and communications cable 234 (Python). When the generator 230 is connected to a catheter, the generator is able to detect whether this is a measuring catheter, used to determine the size of the esophagus, or a treatment catheter, used for ablation. The generator 230 reads from a storage device the type of catheter that is connected to it. The storage device stores various catheter specific information and specific parameters of the size measurement. For example, the storage device contains various generating accessories for each of the diameter sizes. In addition, the generator 230 may cause additional information to be stored, the recommended size of the catheter after self-determination of the size of the balloon or the number of ablations performed. It should be noted that the storage device can be any suitable storage device, such as an EEPROM. When the generator 230 detects a measuring catheter, the generator 230 estimates the diameter of the balloon. In order to reduce the uncertainty in the diameter measurement, a balloon calibration can be performed, using the control 264. During calibration, the volume of gas needed to fully expand the unconstrained balloon is determined, and will be used to determine a calibration constant. Using a mass flow sensor, the generator 230 measures the total gas or mass of fluid required to inflate the measuring balloon to a specific predetermined pressure. This predetermined pressure is a clinically safe pressure to perform the measurement of the size of the esophagus, and is chosen to ensure that balloon inflation within the esophagus can not break the esophagus while stretching and smoothing its lining. In order to initially evacuate all the gas in the balloon, the balloon is inflated to a pressure of approximately 0.28 kg / cm2 (4 psig), then deflated to a negative pressure of approximately up to -0.28 kg / cm2 (-4 psig). ), and then inflated again to 0.28 kg / cm2 (4 psig). The fluid or gas is distributed to the balloon using a pneumatic connecting cable 236. After the depression of the automatic inflation button 240, the generator will distribute air to the balloon according to the inflation pressure of the measuring catheter. It should be noted that the balloons either on the treatment catheter or the measuring catheter can be inflated or deflated using the control buttons 240 and 241. While the balloon is inflated, the balloon pressure can be continuously displayed on the screen 251. Before inserting the measuring balloon into the esophagus to measure its effective diameter at a given inflation pressure (nominal 0.28 kg / cm2 (4 psig)) each balloon is first calibrated in air. The calibration process involves coupling the measuring balloon to pneumatic connecting cable 236 and generator 230 and first drawing a vacuum (typical pressure values in ranges of 0 to -0.42 kg / cm2 (0 to 6 psig)., nominal -0.28 kg / cm2 (4 psig)) to completely collapse the balloon. Next, a mass flow sensor of the generator 230 is used to accurately measure the amount of air needed to fill the balloon (the nominal diameter of 33.7 mm) to 0.28 kg / cm2 (4 psig), thereby resolving the relationship between volume and pressure for that size and shape of a balloon. This calibration information subsequently makes it possible to measure the diameter of the esophagus by measuring the amount of air needed to inflate the balloon to a specific diameter. Once the balloon calibration is completed, the measurement balloon is introduced into the esophagus and relocated to various sites within the esophagus. For each of these positions, the generator 230 estimates the diameter of the balloon and effectively the diameter of the esophagus at the set pressure, and then automatically recommends an ablation balloon catheter diameter to be used subsequently. The generator 230 will then show the diameter of the balloon recommended on the screen 250. After the self-measurement is performed, the system will automatically deflate the catheter balloon to a negative pressure of about -0.14 kg / cm2 (-2 psig). or less. Figure 16 is an exemplary flow chart of the method for measuring the size of the esophagus and finding the position of the more proximal Barrett's esophagus or other areas to be ablated. In step 160, a measuring catheter is connected to the generator. The specific characteristics of the measuring catheter are recognized by the generator from the storage device, such as: if and when the catheter has been used previously, and if the balloon has already fulfilled a maximum number of allowed breaths. The system is ready for balloon calibration in step 161 if the catheter and balloon are optimal for use. For better accuracy, the balloon is unconstrained in air during calibration. In step 163, the balloon goes through the inflation-deflation-inflation cycle, such that the mass flow sensor determines the volume in the balloon at a pre-set pressure. When the calibration is completed, the balloon automatically deflates and is introduced into the esophagus for size measurement, as shown in step 164. The balloon is inflated back into the esophagus in various positions to estimate the internal diameter of the esophagus. In step 165, a first size is shown and a platform per state is indicated on the front panel of the generator. The size measurement routine is repeated at various sites in the esophagus to find the position of the abnormal cells and determine the recommended catheter size, as shown in steps 166, 167 and 168. The generator 230 stores various information obtained at all along the measurement process, such as the estimated diameter of the esophagus, the volume of the calibration balloon, and the number of measurements taken and the diameters measured. Figure 17 illustrates a schematic of an exemplary mechanism for performing balloon size measurement using a mass flow meter and pressure sensors. Using this mechanism, the generator 230 monitors and controls the pressure in the balloon and estimates the volume within the balloon. The pump 171 supplies compressed air to the solenoid valve 172, which can then change the air flow to either inflate or deflate the balloon. Before the gas enters the pump 171, the filter 170 removes the particulate materials from the gas that will enter the pump 171. The mass flow sensor 173 detects the mass of the air entering the system. In addition, the flow sensor 173 could be used to measure the flow of air out of the system for improved safety and accuracy of the system. The pressure within the system is measured by the pressure sensors 174 and 175, with the sensor 175 measuring the atmospheric pressure. Alternatively, instead of sensing the pressure within the system, a positive displacement pump can be used to pump a known amount of fluid or gas into the balloon. When the balloon is deflated, air flows from inside the balloon to the mass flow sensor 173. The filters 176 and 179, connected by the Python cable 178, prevent contamination of the mass flow sensor 173 and the pump 171 during deflation. It should be noted that the size measurement method and system described herein can be used to estimate the internal diameter or other cross-sectional parameters of any lumens or passageways of the body, for example, for lumens within the gastrointestinal tract , the vasculature, the urinary tract, the urogenital system or the pulmonary system. Once the size of the esophagus is estimated for an established pressure, an appropriate treatment catheter is connected to the generator, in order to ablate or erode the abnormal cells within the esophagus. The balloon diameter of the coupled treatment catheter is read from the storage device. It should be noted that, in an alternative modality, the treatment of the esophagus can be performed using the same catheter and balloon used for the measurement of size. In such mode, the generator could recognize the double function of the catheter, size measurement / treatment, and could read the appropriate parameters from the storage device. With reference to Figure 21, after the diameter of the ablation balloon is read from the storage device, the diameter is displayed on the screen 250. Based on the recommended size of the treatment catheter, appropriate adjustments of the generator from the storage device, such as: balloon inflation pressure, balloon volume data, default, maximum or minimum power settings, default, maximum or minimum power settings, or electrode size . In this way, energy and power density levels can be automatically established according to the size of the treatment catheter. The preset power level is displayed on the display 244, while the pre-set power density level is displayed on the display 248. The generator 230 then inflates the treatment catheter balloon coupled to a preset pressure of approximately 0.49 kg / cm2. (7 psig), which will be displayed on screen 251. The adjustment indicator 254 indicates that the unit is in the standby mode, when all the values are being set. In the standby mode, all set values are displayed visually. Throughout the entire ablation procedure, it is desirable to maintain pressure on the balloon at a resting pressure as a safety precaution. If the balloon remains at a pressure of at least 0.457 kg / cm2 (6.5 psig) (typical pressure values in the range of 0.035 to 14.06 kg / cm2 (0.5-200 psig)), the system is then considered "armed". The indicator arm 256 indicates that the displayed values are the set values and the system is ready to distribute the RF energy. The RF on / off switch 238 indicates and controls when the RF power is being distributed. In one embodiment, the generator 230 distributes and controls the power until the desired energy density is distributed. The generator maintains a set power on each electrode, and is capable of sequentially distributing the energy to each electrode on the treatment catheter. When the desired energy is distributed to all the desired sites, the completed indicator 258 indicates that the ablation is completed. A user may have the ability to adjust the power and density of energy distributed to the tissue. The output power can be set and adjusted using buttons 241 above and below. The effective potency distributed to the tissue from the catheter guides, is displayed on the power screen 244. Similarly, the energy density is set using the button 246 above and below, and the distributed produced energy density, is displayed on the LED screen 248. The status display 252 of the The system is an LCD panel and displays the operational codes and user instructions. For example, panel 252 displays the "calibration" function before performing balloon self-measurement. Panel 252 also displays error codes and an error message with instructions to resolve errors. The reset button 262 can be depressed to reset the system if an error occurs. In addition, panel 252 indicates when the system is in standby mode. Fault indicator 260 indicates when the system is in failure mode and a non-recoverable error was detected. It should be noted that the front panel of the generator 230 can visually display, control and indicate the different functions of the exemplary functions described herein. In one embodiment, the pedal type foot switch 232 is coupled to the rear panel of the generator and can control the inflation system and the RF distribution. The 232 pedal is capable of duplicating certain functions of the front panel buttons of the generator. For example, the foot switch 232 can duplicate the RF on / off button 238 and / or the balloon self-inflating buttons 240 and 241, up and down. Figure 18 is an exemplary flow diagram of the ablation procedure according to one embodiment of the invention. When the ablation catheter is connected to the generator, in step 180, the generator recognizes the specific characteristics of the ablation catheter and is ready to inflate the balloon, in step 181. The catheter is armed at 182 and the balloon is inflated and maintained at a pressure of approximately 0.49 kg / cm2 (7 psig) (typical pressure values in the range of 0.035 to 14.06 kg / cm2 (0.5 to 200 psig) .If the balloon pressure is stable, the ARM indicator is ignited on the front panel display of the generator In step 183, once the ARM light is on, the generator is ready to distribute the energy to the electrodes of the ablation catheter.The energy is subsequently automatically distributed by the generator 230, As shown in step 184. After each ablation, the balloon is automatically deflated in order to reposition the balloon and the electrodes in another ablation site within the esophagus. is performed as necessary in step 186. After treating all desired sites within the esophagus, ablation is completed in step 188. It should be noted that the generator distributes energy only after the system meets certain safety checks. , as shown in steps 185 and 187. The generator periodically monitors the inflation of the balloon, the energy parameters and the total integrity of the system before and during the treatment of the tissue. These safety procedures ensure that the generator can safely distribute the required power. For example, the generator will not distribute energy to the electrodes unless the impedance and the temperature of the tissue are within acceptable parameters. Similarly, the generator monitors any pressure fluctuations within the treatment balloon. In one embodiment, generator 230 will only distribute energy if the balloon within the esophagus is maintained at a required pressure at rest of approximately 0.49 ± 0.07 kg / cm2 (7 ± 1 psig). This safety check ensures that there is no connection leak or balloon leak and the esophagus is completely distended before ablation. Another precaution is taken regarding the deflation of the balloon between ablations. In order to ensure that the balloon is completely deflated before repositioning it in a different place within the esophagus, the balloon is deflated at a pressure of approximately -0.14 kg / cm2 (-2 psig). In one embodiment, the generator 230 monitors and controls the power sent to the electrodes and ensures that a constant energy is distributed. A proportional integral derivative controller (PID) controls the amount of energy by increasing the energy level, and inherently the voltage level, until it reaches an established target value. In one mode, the PID controller controls the amount of energy by gradually increasing the energy level. In a particularly advantageous embodiment, the PID controller controls the amount of energy by rapidly increasing the energy level. In addition, to better control the depth of ablation, the PID controller ensures that the desired energy level is reached within a certain time window. In one embodiment, the generator is adapted to control the amount of energy distributed to the tissue over time, based on the measured diameter of the esophagus. In addition, the generator can be adapted to normalize the density of energy distributed to the tissue over time, based on the measured diameter of the esophagus, so that equivalent energy densities are distributed (e.g., energy per unit are of the surface area of the electrode {.J / cm2.}.) to the esophagus of different diameters. In another embodiment, the generator is adapted to control the amount of energy distributed to the tissue over time, based on the measured diameter of the esophagus, so that equivalent energy densities (e.g., power per unit area of the surface area of the electrode { W / cm2.}.) are distributed to esophagus of different diameters. In order to effectively erode the mucosal lining of the esophagus, the system described herein controls the total energy delivered to the esophageal tissue and the amount of time for which the energy is distributed, as described above. Other methods can similarly be employed to erode a desired surface area rapidly and circumferentially, while controlling the depth of ablation. The generator 230 can be manually controlled by a user such that the amount of energy density distributed to the esophageal tissue can be monitored over time.

As such, the generator 230 is adapted to allow the user to select an appropriate energy density that is to be distributed to the tissue in a short burst. In one embodiment, the time for an effective treatment is less than one second. In another mode, the time is approximately 300 milliseconds. In order to effectively remove the abnormal cells in the esophagus, the energy must be applied such that a physiological change occurs at the cellular level within the lining of the esophagus. The methods of tracing the characteristics of the esophageal tissue and the changes in its cellular characteristics, include the monitoring of tissue impedance and / or tissue temperature. The ablation time could then be adjusted based on the individual characteristics of the tissue and its measured impedance and / or temperature values. Figure 19 illustrates a graphical representation of the impedance measurements during ablation over time. During ablation, tissue temperature rises, which causes a decrease in tissue resistivity. This drop in impedance from an initial impedance value is represented by the exemplary reference points A and B. If the ablation continues beyond reference point B, the cell membranes of the tissue rupture, such that drying occurs. the cells and tissue resistivity increases. The increased impedance value, exemplary measured during this period of time, is shown by the reference point C. In order to control the depth of ablation and the degree of treatment in terms of the total volume of the dried tissue, the generator 230 monitors the changes in the measured tissue impedance values. As such, the generator 230 distributes the energy to the tissue in a time window defined by the tissue impedance measurements. For example, in one embodiment, the generator 230 can erode only by the time it takes the tissue to reach an absolute impedance target. For example, the target impedance value is in the range of approximately 0.5 to 10 ohms. In yet another embodiment, the generator 230 can erode only until the impedance value decreases a predetermined percentage from the initial impedance value of the tissue before ablation. In yet another embodiment, the time of the ablation may depend on the point at which the impedance values reach a point of inflection on the graph illustrated in Figure 19, for example, when the impedance values are between the reference points B and C. As such, the energy distribution could stop when the impedance reaches its minimum value, at which point it begins to increase. In yet another embodiment, the ablation time can be defined by the impedance value that exceeds a particular level. If the tissue impedance value reaches levels greater than the initial impedance value, as shown by the exemplary reference point D, the degree of treatment can reach levels such that the esophageal wall is ruptured. As such, it may be desirable to cease the distribution of energy to the tissue before the impedance reaches its initial value, for example, the reference value C. Figure 20 illustrates a graphical representation of the temperature of the fabric over time. When the tissue receives RF energy, heat is being generated. Ti, T2 and T3 represent temperature curves of different sensors placed in different places inside or outside the tissue that is going to be subjected to ablation. For optimal ablation with controlled depth, the ablation time must be controlled such that the temperature of the tissue is less than 100 ° C. For example, if the desired ablation reaches within the tissue approximately 0.5 to 1 mm from the surface, the generator 230 controls the ablation time, such that the tissue temperature is between 65 ° C and 95 ° C. Alternatively, the ablation time could be defined by the amount of time it takes the tissue to warm up to a pre-set target temperature. In this method, the generator 230 monitors the temperature of the fabric and, when the fabric has reached a certain temperature, the generator 230 stops the distribution of energy to the fabric. While the exemplary embodiments have been described in some detail, by way of example and for clarity of understanding, those skilled in the art will recognize that a variety of modifications, adaptations and changes may be employed. Therefore, the scope of the present invention should be limited only to the appended claims. It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (19)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. An apparatus for treating tissue within a body lumen characterized in that it comprises: an electrode structure adapted to be placed on a tissue surface within of the body lumen, wherein the structure of the electrode is coupled to an expansion member; and a generator to produce and distribute energy to the electrode structure; wherein the generator is adapted to automatically inflate the expansion member within the body lumen and control the pressure within the expansion member during tissue treatment.
2. 2. The apparatus according to claim 1, characterized in that the expansion number is a balloon coupled to a catheter.
3. The apparatus according to claim 1, characterized in that it also comprises a storage device for storing accessories of the generator.
4. The apparatus according to claim 3, characterized in that the storage device is an EEPROM.
5. The apparatus according to claim 1, characterized in that it further comprises a pump for automatically inflating or deflating the expansion member.
6. The apparatus according to claim 1, characterized in that the generator is adapted to determine an internal diameter of the body lumen using an inflatable balloon.
7. The apparatus according to claim 6, characterized in that the generator is adapted to control the amount of energy distributed to the tissue over time, based on the measured diameter of the esophagus.
8. The apparatus according to claim 6, characterized in that the generator is adapted to normalize the energy density distributed to the tissue based on the measured diameter of the esophagus.
9. The apparatus according to claim 6, characterized in that the generator is adapted to control the amount of energy distributed to the tissue over time, based on the measured diameter of the esophagus.
10. 10. The apparatus according to claim 1, characterized in that the generator is adapted to control the energy distributed to the electrode structure.
11. The apparatus according to claim 1, characterized in that the generator is adapted to control the energy distributed to the electrode structure.
12. 12. The apparatus according to claim 1, characterized in that the generator is adapted to normalize the amount of energy distributed to the tissue over time, based on the measured diameter of the esophagus.
13. The apparatus according to claim 1, characterized in that the generator is adapted to detect if a catheter is coupled to it and to identify a characteristic of the coupled catheter.
14. The apparatus according to claim 13, characterized in that it further comprises a storage device adapted to store information regarding the coupled catheter.
15. 15. The apparatus according to claim 1, characterized in that it further comprises a foot switch coupled to the generator and adapted to control the energy distributed to the electrode structure.
16. 16. The apparatus according to claim 1, characterized in that it further comprises a screen for visually displaying the information to a user.
17. The apparatus according to claim 1, characterized in that the generator is adapted to be manually controlled by a user, such that the user controls the energy distributed to the electrode structure, over time.
18. The apparatus according to claim 1, characterized in that it further comprises an integral, proportional derivative controller, adapted to gradually increase the energy distributed to the electrode structure until it reaches an established target value.
19. 19. An apparatus for treating tissue within a body lumen, characterized in that it comprises: an electrode structure adapted to be placed on a tissue surface within the body lumen, wherein the electrode structure is configured to an expansion member; and a generator for producing, distributing and controlling the energy distributed to the electrode structure; wherein the generator is adapted to determine an internal diameter of the body lumen.