Patent Publication Number: US-7717115-B2

Title: Delivery methods and devices for implantable bronchial isolation devices

Description:
REFERENCE TO PRIORITY DOCUMENT 
   This application claims priority of co-pending U.S. Provisional Patent Application Serial No. 60/429,902 entitled “Implantable Bronchial Isolation Devices”, filed Nov. 27, 2002. Priority of the aforementioned filing date is hereby claimed, and the disclosure of the Provisional Patent Application is hereby incorporated by reference in its entirety. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates generally to methods and devices for use in performing pulmonary procedures and, more particularly, to devices and procedures for treating lung diseases. 
   2. Description of the Related Art 
   Certain pulmonary diseases, such as emphysema, reduce the ability of one or both lungs to fully expel air during the exhalation phase of the breathing cycle. Such diseases are accompanied by chronic or recurrent obstruction to air flow within the lung. One of the effects of such diseases is that the diseased lung tissue is less elastic than healthy lung tissue, which is one factor that prevents full exhalation of air. During breathing, the diseased portion of the lung does not fully recoil due to the diseased (e.g., emphysematic) lung tissue being less elastic than healthy tissue. Consequently, the diseased lung tissue exerts a relatively low driving force, which results in the diseased lung expelling less air volume than a healthy lung. 
   The problem is further compounded by the diseased, less elastic tissue that surrounds the very narrow airways that lead to the alveoli, which are the air sacs where oxygen-carbon dioxide exchange occurs. The diseased tissue has less tone than healthy tissue and is typically unable to maintain the narrow airways open until the end of the exhalation cycle. This traps air in the lungs and exacerbates the already-inefficient breathing cycle. The trapped air causes the tissue to become hyper-expanded and no longer able to effect efficient oxygen-carbon dioxide exchange. 
   In addition, hyper-expanded, diseased lung tissue occupies more of the pleural space than healthy lung tissue. In most cases, a portion of the lung is diseased while the remaining part is relatively healthy and, therefore, still able to efficiently carry out oxygen exchange. By taking up more of the pleural space, the hyper-expanded lung tissue reduces the amount of space available to accommodate the healthy, functioning lung tissue. As a result, the hyper-expanded lung tissue causes inefficient breathing due to its own reduced functionality and because it adversely affects the functionality of adjacent healthy tissue. 
   Lung reduction surgery is a conventional method of treating emphysema. However, such a conventional surgical approach is relatively traumatic and invasive, and, like most surgical procedures, is not a viable option for all patients. 
   Some recently proposed treatments for emphysema or other lung ailments include the use of devices that isolate a diseased region of the lung in order to modify the air flow to the targeted lung region or to achieve volume reduction or collapse of the targeted lung region. According to such treatments, one or more bronchial isolation devices are implanted in airways feeding the targeted region of the lung. The bronchial isolation device regulates fluid flow through the bronchial passageway in which the bronchial isolation device is implanted. The bronchial isolation devices can be, for example, one-way valves that allow flow in the exhalation direction only, occluders or plugs that prevent flow in either direction, or two-way valves that control flow in both directions. 
   The following references describe exemplary bronchial isolation devices: U.S. Pat. No. 5,954,766 entitled “Body Fluid Flow Control Device”; U.S. patent application Ser. No. 09/797,910, entitled “Methods and Devices for Use in Performing Pulmonary Procedures”; and U.S. patent application Ser. No. 10/270,792, entitled “Bronchial Flow Control Devices and Methods of Use”. The foregoing references are all incorporated by reference in their entirety and are all assigned to Emphasys Medical, Inc., the assignee of the instant application. 
   The bronchial isolation device can be implanted in a target bronchial passageway using a delivery catheter that is placed through the trachea (via the mouth or the nasal cavities) and to the target location in the bronchial passageway. It would be advantageous to develop improved methods and devices for delivering bronchial isolation devices into the lung of a patient. 
   SUMMARY 
   Disclosed is an apparatus for deploying a bronchial isolation device in a bronchial passageway in a lung of a patient, comprising an outer shaft having a distal end; a housing coupled to the distal end of the outer shaft and configured to receive the bronchial device; an inner shaft slidably disposed within the outer shaft; and a handle adapted to move the outer shaft relative to both the inner shaft and the handle while the inner shaft remains fixed relative to the handle so as to eject the bronchial isolation device from the housing. 
   Also disclosed is an apparatus for deploying a bronchial isolation device in a bronchial passageway in a lung of a patient, comprising an outer shaft having a distal end; a housing coupled to the distal end of the outer shaft and configured to receive the bronchial device; an ejection member movably disposed in the housing; and a handle adapted to cause relative movement between the housing and the ejection member so as to eject the bronchial isolation device from the housing. Relative movement between the housing and the ejection member is limited to prevent the ejection member from moving substantially outside of the housing. 
   Also disclosed is an apparatus for delivering a device into a body passageway, comprising a handle; an outer shaft movably coupled to the handle; an inner shaft slidably disposed within the outer shaft and fixedly coupled to the handle, the handle adapted to move the outer shaft relative to both the inner shaft and the handle while the inner shaft remains fixed relative to the handle; and a sheath attached to the handle and disposed over a portion of the outer shaft such that the outer shaft is free to slide within the sheath. 
   Also disclosed is a method of deploying a bronchial device in a bronchial passageway in a patient&#39;s lung, the method comprising: providing a delivery device having an outer shaft, an inner shaft and a handle; coupling the bronchial isolation device to a housing on a distal end of the outer shaft and a inner shaft; advancing the delivery catheter into the patient&#39;s lung with the housing carrying the bronchial device until the housing is positioned in the bronchial passageway; and moving the outer shaft in a proximal direction relative to the inner shaft and the handle while the inner shaft remains fixed relative to the handle to release the bronchial isolation device from the housing. 
   Also disclosed is a method of deploying a bronchial device in a bronchial passageway in a patient&#39;s lung, the method comprising providing a delivery device having an outer shaft, a housing coupled to a distal end of the outer shaft, and an ejection member movably disposed in the housing; advancing the delivery catheter into the patient&#39;s lung with the housing carrying the bronchial device until the housing is positioned in the bronchial passageway; and moving the ejection member relative to the housing to eject the bronchial isolation device from the housing, wherein the ejection member is substantially limited from moving outside of the housing. 
   Other features and advantages of the present invention should be apparent from the following description of various embodiments, which illustrate, by way of example, the principles of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows an anterior view of a pair of human lungs and a bronchial tree with a bronchial isolation device implanted in a bronchial passageway to bronchially isolate a region of the lung. 
       FIG. 2  illustrates an anterior view of a pair of human lungs and a bronchial tree. 
       FIG. 3  illustrates a lateral view of the right lung. 
       FIG. 4  illustrates a lateral view of the left lung. 
       FIG. 5  illustrates an anterior view of the trachea and a portion of the bronchial tree. 
       FIG. 6  shows a perspective view of a bronchoscope. 
       FIG. 7  shows an enlarged view of a distal region of a bronchoscope. 
       FIG. 8  shows a delivery catheter for delivering a bronchial isolation device to a target location in a body passageway. 
       FIG. 9  shows a perspective view of a distal region of the delivery catheter. 
       FIG. 10A  shows a plan, side view of the distal region of the delivery catheter. 
       FIG. 10B  shows a cross-sectional view of the delivery catheter along line  10 B- 10 B of  FIG. 10A . 
       FIG. 11A  shows the delivery catheter containing a bronchial isolation device in a housing, which is positioned at a location L of a bronchial passageway. 
       FIG. 11B  shows the delivery catheter and the deployed bronchial isolation device at the location L of the bronchial passageway. 
       FIG. 12  shows a cross-sectional view of a delivery catheter deployed in a bronchial location that requires the delivery catheter&#39;s distal end to bend at an acute angle. 
       FIG. 13  shows a cross-sectional view of the distal end of the delivery catheter with a limited-travel flange fully retracted into the delivery housing. 
       FIG. 14  shows a cross-sectional view of the distal end of the delivery catheter with a limited-travel flange fully extended. 
       FIG. 15  shows a side view of one embodiment of an actuation handle of the delivery catheter. 
       FIG. 16  shows a cross-sectional, side view of the actuation handle of  FIG. 15  with an actuation member in an initial position. 
       FIG. 17  shows a cross-sectional, side view of a portion of the actuation handle of  FIG. 15  with the actuation member distal of the initial position. 
       FIG. 18  shows an enlarged view of the distal region of the bronchoscope with the delivery catheter&#39;s distal end protruding outward from the working channel. 
       FIG. 19  shows another embodiment of the delivery catheter handle configured for transcopic delivery. 
       FIG. 20  shows the delivery catheter of  FIG. 19  positioned within the working channel of the bronchoscope with the catheter handle protruding from the bronchoscope. 
       FIG. 21  shows an embodiment of the delivery catheter that includes a deployment sheath. 
       FIG. 22  shows a partial view of the delivery catheter of  FIG. 21  positioned through an anesthesia adapter. 
   

   DETAILED DESCRIPTION 
   Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which the invention(s) belong. It should be noted that the various devices and methods disclosed herein are not limited to the treatment of emphysema, and may be used for various other lung diseases. 
   Disclosed are various devices and methods for delivering one or more bronchial isolation devices (which are sometimes referred to herein as flow control devices) to a location in a bronchial passageway. The bronchial isolation device is delivered to a target location in the bronchial passageway by mounting the bronchial isolation device in a housing at the distal end of a delivery catheter and then inserting the delivery catheter into the bronchial passageway. Once the housing is positioned at a target location in the bronchial passageway, the bronchial isolation device is ejected from the housing and deployed within the passageway. In the example shown in  FIG. 1 , the distal end of the delivery catheter  110  is inserted into the patient&#39;s mouth or nose, through the trachea, and down to a target location in the bronchial passageway  517 . For clarity of illustration,  FIG. 1  does not show the housing in which the device is contained. 
   The following references describe exemplary bronchial isolation devices and delivery devices: U.S. Pat. No. 5,954,766 entitled “Body Fluid Flow Control Device”; U.S. patent application Ser. No. 09/797,910, entitled “Methods and Devices for Use in Performing Pulmonary Procedures”; U.S. patent application Ser. No. 10/270,792, entitled “Bronchial Flow Control Devices and Methods of Use”; and U.S. patent application Ser. No. 10/448,154, entitled “Guidewire Delivery of Implantable Bronchial Isolation Devices in Accordance with Lung Treatment”. The foregoing references are all incorporated by reference in their entirety and are all assigned to Emphasys Medical, Inc., the assignee of the instant application. 
   Exemplary Lung Regions 
   Throughout this disclosure, reference is made to the term “lung region”. As used herein, the term “lung region” refers to a defined division or portion of a lung. For purposes of example, lung regions are described herein with reference to human lungs, wherein some exemplary lung regions include lung lobes and lung segments. Thus, the term “lung region” as used herein can refer, for example, to a lung lobe or a lung segment. Such nomenclature conform to nomenclature for portions of the lungs that are known to those skilled in the art. However, it should be appreciated that the term “lung region” does not necessarily refer to a lung lobe or a lung segment, but can refer to some other defined division or portion of a human or non-human lung. 
     FIG. 2  shows an anterior view of a pair of human lungs  210 ,  215  and a bronchial tree  220  that provides a fluid pathway into and out of the lungs  210 ,  215  from a trachea  225 , as will be known to those skilled in the art. As used herein, the term “fluid” can refer to a gas, a liquid, or a combination of gas(es) and liquid(s). For clarity of illustration,  FIG. 2  shows only a portion of the bronchial tree  220 , which is described in more detail below with reference to  FIG. 5 . 
   Throughout this description, certain terms are used that refer to relative directions or locations along a path defined from an entryway into the patient&#39;s body (e.g., the mouth or nose) to the patient&#39;s lungs. The path of airflow into the lungs generally begins at the patient&#39;s mouth or nose, travels through the trachea into one or more bronchial passageways, and terminates at some point in the patient&#39;s lungs. For example,  FIG. 2  shows a path  202  that travels through the trachea  225  and through a bronchial passageway into a location in the right lung  210 . The term “proximal direction” refers to the direction along such a path  202  that points toward the patient&#39;s mouth or nose and away from the patient&#39;s lungs. In other words, the proximal direction is generally the same as the expiration direction when the patient breathes. The arrow  204  in  FIG. 2  points in the proximal or expiratory direction. The term “distal direction” refers to the direction along such a path  202  that points toward the patient&#39;s lung and away from the mouth or nose. The distal direction is generally the same as the inhalation or inspiratory direction when the patient breathes. The arrow  206  in  FIG. 2  points in the distal or inhalation direction. 
   The lungs include a right lung  210  and a left lung  215 . The right lung  210  includes lung regions comprised of three lobes, including a right upper lobe  230 , a right middle lobe  235 , and a right lower lobe  240 . The lobes  230 ,  235 ,  240  are separated by two interlobar fissures, including a right oblique fissure  226  and a right transverse fissure  228 . The right oblique fissure  226  separates the right lower lobe  240  from the right upper lobe  230  and from the right middle lobe  235 . The right transverse fissure  228  separates the right upper lobe  230  from the right middle lobe  235 . 
   As shown in  FIG. 2 , the left lung  215  includes lung regions comprised of two lobes, including the left upper lobe  250  and the left lower lobe  255 . An interlobar fissure comprised of a left oblique fissure  245  of the left lung  215  separates the left upper lobe  250  from the left lower lobe  255 . The lobes  230 ,  235 ,  240 ,  250 ,  255  are directly supplied air via respective lobar bronchi, as described in detail below. 
     FIG. 3  is a lateral view of the right lung  210 . The right lung  210  is subdivided into lung regions comprised of a plurality of bronchopulmonary segments. Each bronchopulmonary segment is directly supplied air by a corresponding segmental tertiary bronchus, as described below. The bronchopulmonary segments of the right lung  210  include a right apical segment  310 , a right posterior segment  320 , and a right anterior segment  330 , all of which are disposed in the right upper lobe  230 . The right lung bronchopulmonary segments further include a right lateral segment  340  and a right medial segment  350 , which are disposed in the right middle lobe  235 . The right lower lobe  240  includes bronchopulmonary segments comprised of a right superior segment  360 , a right medial basal segment (which cannot be seen from the lateral view and is not shown in  FIG. 3 ), a right anterior basal segment  380 , a right lateral basal segment  390 , and a right posterior basal segment  395 . 
     FIG. 4  shows a lateral view of the left lung  215 , which is subdivided into lung regions comprised of a plurality of bronchopulmonary segments. The bronchopulmonary segments include a left apical segment  410 , a left posterior segment  420 , a left anterior segment  430 , a left superior segment  440 , and a left inferior segment  450 , which are disposed in the left lung upper lobe  250 . The lower lobe  255  of the left lung  215  includes bronchopulmonary segments comprised of a left superior segment  460 , a left medial basal segment (which cannot be seen from the lateral view and is not shown in  FIG. 4 ), a left anterior basal segment  480 , a left lateral basal segment  490 , and a left posterior basal segment  495 . 
     FIG. 5  shows an anterior view of the trachea  325  and a portion of the bronchial tree  220 , which includes a network of bronchial passageways, as described below. The trachea  225  divides at a lower end into two bronchial passageways comprised of primary bronchi, including a right primary bronchus  510  that provides direct air flow to the right lung  210 , and a left primary bronchus  515  that provides direct air flow to the left lung  215 . Each primary bronchus  510 ,  515  divides into a next generation of bronchial passageways comprised of a plurality of lobar bronchi. The right primary bronchus  510  divides into a right upper lobar bronchus  517 , a right middle lobar bronchus  520 , and a right lower lobar bronchus  422 . The left primary bronchus  415  divides into a left upper lobar bronchus  525  and a left lower lobar bronchus  530 . Each lobar bronchus  517 ,  520 ,  522 ,  525 ,  530  directly feeds fluid to a respective lung lobe, as indicated by the respective names of the lobar bronchi. The lobar bronchi each divide into yet another generation of bronchial passageways comprised of segmental bronchi, which provide air flow to the bronchopulmonary segments discussed above. 
   As is known to those skilled in the art, a bronchial passageway defines an internal lumen through which fluid can flow to and from a lung or lung region. The diameter of the internal lumen for a specific bronchial passageway can vary based on the bronchial passageway&#39;s location in the bronchial tree (such as whether the bronchial passageway is a lobar bronchus or a segmental bronchus) and can also vary from patient to patient. However, the internal diameter of a bronchial passageway is generally in the range of 3 millimeters (mm) to 10 mm, although the internal diameter of a bronchial passageway can be outside of this range. For example, a bronchial passageway can have an internal diameter of well below 1 mm at locations deep within the lung. The internal diameter can also vary from inhalation to exhalation as the diameter increases during inhalation as the lungs expand, and decreases during exhalation as the lungs contract. 
   Bronchial Isolation Device Delivery System 
   As discussed above, the bronchial isolation device is deployed in the bronchial passageway using a delivery catheter  110 , which is inserted into the bronchial passageway through the patient&#39;s trachea. In one embodiment, the delivery catheter  110  is inserted directly into the trachea and bronchial passageway. In another embodiment, shown in  FIG. 1 , a bronchoscope  120  assists in the insertion of the delivery catheter  110  through the trachea and into the bronchial passageway. The method that uses the bronchoscope  120  is referred to as the “transcopic” method. According to the transcopic method, the delivery catheter  110  is inserted into the working channel of the bronchoscope  120 , which is deployed to the bronchial passageway  517  either before or after the delivery catheter has been inserted into the bronchoscope  120 . 
   As shown in  FIGS. 1 and 6 , in an exemplary embodiment the bronchoscope  120  has a steering mechanism  125 , a delivery shaft  130 , a working channel entry port  135 , and a visualization eyepiece  140 .  FIG. 1  shows the bronchoscope  120  positioned with its distal end at the right primary bronchus  510 . The delivery catheter  110  is positioned within the bronchoscope  120  such that the delivery catheter&#39;s distal end and the attached bronchial isolation device  115  protrude outward from the distal end of the bronchoscope  120 , as shown in  FIG. 1 . 
     FIG. 6  shows an enlarged view of the bronchoscope  120 , including the steering mechanism  125 , delivery shaft  130 , working channel entry port  135 , and visualization eyepiece  140 . In addition, the bronchoscope can also include a fiber optic bundle mounted inside the length of the bronchoscope for transferring an image from the distal end to the eyepiece  140 . In one embodiment, the bronchoscope also includes a camera or charge-coupled device (CCD) for generating an image of the bronchial tree.  FIG. 7  shows an enlarged view of the distal portion of the bronchoscope  120 . A working channel  710  (sometimes referred to as a biopsy channel) extends through the delivery shaft  130  and communicates with the entry port  135  (shown in  FIG. 6 ) at the proximal end of the bronchoscope  120 . The working channel  710  can sometimes be formed by an extruded plastic tube inside the body of the bronchoscope  120 . The bronchoscope  120  can also include various other channels, such as a visualization channel  720  that communicates with the eyepiece  140  and one or more illumination channels  730 . It should be appreciated that the bronchoscope can have a variety of configurations and is not limited to the embodiment shown in the figures. For example, in an alternative embodiment, the working channel  710  may be formed of a flexible material and temporarily or permanently attached to the outside of the delivery shaft  130 . 
     FIG. 8  shows one embodiment of the delivery catheter  110  for delivering and deploying the bronchial isolation device  115  to a target location in a bronchial passageway. The delivery catheter  110  has a proximal end  810  and a distal end  815  that can be deployed to a target location in a patient&#39;s bronchial passageway, such as through the trachea. The catheter  110  has an elongated outer shaft  820  and an elongated inner shaft  825  that is slidably positioned within the outer shaft  820  such that the outer shaft  820  can slidably move relative to the inner shaft  825  along the length of the catheter, as described in more detail below. 
   The following references describe exemplary delivery devices: U.S. Pat. No. 5,954,766 entitled “Body Fluid Flow Control Device”; U.S. patent application Se. No. 09/797,910, entitled “Methods and Devices for Use in Performing Pulmonary Procedures”; U.S. patent application Ser. No. 10/270,792, entitled “Bronchial Flow Control Devices and Methods of Use”; and U.S. patent application Ser. No. 10/448,154, entitled “Guidewire Delivery of Implantable Bronchial Isolation Devices in Accordance with Lung Treatment”. The foregoing references are all incorporated by reference in their entirety and are all assigned to Emphasys Medical, Inc., the assignee of the instant application. 
   With reference still to  FIG. 8 , an actuation handle  830 , is located at the proximal end  810  of the catheter  110 . The actuation handle  830  can be actuated to slidably move the outer shaft  820  in a proximal direction relative to the inner shaft  825  with the inner shaft  825  remaining fixed relative to the actuation handle  830 . During such movement, the outer shaft  820  slides over the inner shaft  825 .  FIG. 8  shows a schematic view of the actuation handle  830 , which is described in more detail below. Generally, the handle  830  includes a first piece  835  and a second actuation piece  840 , which is moveable relative to the first piece  835 . The outer shaft  820  of the catheter  110  can be moved relative to the inner shaft  825  by moving the first piece  835  of the handle  830  relative to the second piece  840 . 
   The inner shaft  825  of the catheter  110  can include a central guidewire lumen (not shown) that extends through the entire length of the catheter  110 . The central guidewire lumen of the inner shaft  825  is sized to receive a guidewire, which can be used during deployment of the catheter  110  to guide the catheter  110  to a location in a bronchial passageway. 
   With reference still to  FIG. 8 , a housing  850  is located at or near a distal end of the catheter  110  for holding therein the bronchial isolation device  115 . In one embodiment, the housing  850  is attached to a distal end of the outer shaft  820  of the catheter  110  but not attached to the inner shaft  825 , which extends axially through the housing. The housing  850  defines an inner cavity that is sized to receive the bronchial isolation device  115  therein. 
     FIG. 9  shows an enlarged, perspective view of the distal portion of the catheter  110  where the housing  850  is located.  FIG. 10A  shows a plan, side view of the distal portion of the catheter  110  where the housing  850  is located. As shown in  FIGS. 9 and 10A , the housing  850  is shaped to receive the bronchial isolation device therein and is open at a distal end and closed at a proximal end. The inner shaft  825  of the catheter  110  protrudes through the housing  850  and can slidably move relative to the housing  850 . An ejection member, such as a flange  910 , is attached at or near a distal end of the inner shaft  825 . The flange  910  is sized such that it can be received into the housing  850  so that the flange  910  can be withdrawn into the housing  850  to abut a proximal end of the housing.  FIGS. 9 and 10A  show the flange  910  positioned outside of the housing  850 . 
   As described below, the ejection member can be used to eject the bronchial isolation device  115  from the housing  850 . The housing can be manufactured of a rigid material, such as steel. The housing  850  can also be flexible or collapsible. Although the housing  850  is shown having a cylindrical shape, it should be appreciated that the housing  850  can have other shapes that are configured to receive the bronchial isolation device therein. 
   In one embodiment, a sizing element  925  is located at or near the housing  850 , as shown in  FIGS. 10A and 10B . (For clarity of illustration,  FIG. 10B  does not show the bronchial isolation device  115  mounted in the housing  850  and does not show the inner shaft  825  of the delivery catheter.) The sizing element  925  can be used to determine whether the bronchial isolation device  115  in the housing  850  will fit within a particular bronchial passageway in a working manner. The sizing element  925  comprises one or more extensions, such as first extensions  930   a  and second extensions  930   b  that define distances L 1  and L 2 , respectively. That is, the opposed, outer tips of the extensions  930   a  are separated by a distance L 1  and the opposed, outer tips of the extensions  930   b  are separated by a distance L 2 . The distance L 1  corresponds to the diameter of the larger end of the functional diameter range of the bronchial isolation device  115 . That is, the distance L 1  is substantially equal to the largest possible diameter for a bronchial passageway in which the bronchial isolation device can be functionally deployed. The distance L 2  corresponds to the diameter of the lower end of the functional diameter range of the bronchial isolation device  115 . That is, the distance L 2  is substantially equal to the smallest possible diameter for a bronchial passageway in which the bronchial isolation device  115  can be functionally deployed. It should be appreciated that the extensions  930  can take on a variety of structures and shapes. For example,  FIGS. 10A and 10B  shows the extensions  930  comprising elongate prongs that extend radially outward from the catheter or the housing  850 . 
   In another embodiment, shown in  FIG. 9 , the extensions  930  of the sizing element  925  comprise two or more loops  931   a  and  931   b , which correspond to the extensions  930   a  and  930   b , respectively. Each loop  931  forms an ellipse having a long axis of a predetermined length. In the illustrated embodiment, the loop  931   a  has a long axis of length L 1  that is greater than the length L 2  of the long axis of the second loop  931   b . Thus, the larger length L 1  of loop  931   a  corresponds to the diameter of the larger end of the functional diameter range of the bronchial isolation device  115 . The shorter length L 2  of loop  931   b  corresponds to the diameter of the lower end of the functional diameter range of the bronchial isolation device. 
   As the delivery catheter  110  is inserted into the bronchial passageway, the sizing element  925  is used to determine whether or not the bronchial passageway is within the functional range of the bronchial isolation device  115 . For a bronchial passageway in which the sizing element is positioned, if the opposed tips of the longer extensions  930   a  (e.g., the diameter loop  931   a ) cannot simultaneously contact the wall of the bronchial passageway, then the bronchial isolation device  115  is too small to be implanted in that passageway. In other words, the bronchial passageway is too large for the bronchial isolation device if the tips of the longer extensions  930   a  cannot simultaneously contact the bronchial wall when the extensions  930   a  are centrally positioned within the bronchial passageway. If the opposed tips of the shorter extensions  930   b  can simultaneously contact the wall of the bronchial passageway, then the bronchial isolation device  115  is too large to be implanted in the bronchial passageway in a working manner. 
   The extensions  930 , such as the loops  931 , can be constructed of various materials. In one embodiment, the extensions are constructed of wire, etched from a flat plate, or by other methods. The extensions  930  can be made of a flexible material, such as Nitinol, or a polymer or other flexible material, such that the extensions fold down when inserted into or retracted into the working channel of the bronchoscope. In one embodiment, the extensions are manufactured of Pebax, which is a polyether-block co-polyamide polymer. Other flexible resins can be used as well. Other configurations and shapes of the sizing element  925  are contemplated, such as standing struts rather than loops, etc. 
   In use, the bronchial isolation device  115  is first inserted into the housing  850 . The bronchial isolation device  115  can be inserted into the housing according to various methods and devices, some of which are described in U.S. patent application Ser. No. 10/270,792, entitled “Bronchial Flow Control Devices and Methods of Use”, which is assigned to Emphasys Medical, Inc., the assignee of the instant application. After the bronchial isolation device  115  is inserted into the housing, the distal end of the delivery catheter  110  is deployed into a bronchial passageway via the trachea such that the housing  850  is located at or near the target location in the bronchial passageway, as shown in  FIG. 11A . Once the delivery catheter  110  and the attached bronchial isolation device  115  are located at the target location, an operator can eject the bronchial isolation device  115  from the housing  850  into the bronchial passageway. 
   This process is described with reference to  FIG. 11A and 11B .  FIG. 11A  shows a cross-sectional view of a bronchial passageway  1110  with the deliver catheter  110  positioned therein. The distal end of the delivery catheter  110 , including the housing  850 , is located at or near the target location L. Once the catheter is positioned as such, an operator actuates the catheter handle  830  to slidably move the outer catheter member  820  in a proximal direction relative to the location L, while maintaining the location of the bronchial isolation device  115 , inner shaft  825 , and flange  910  fixed with respect to the location L. The proximal movement of the outer shaft  820  causes the attached housing  850  to also move in a proximal direction, while the flange  910  prevents the bronchial isolation device  115  from moving in the proximal direction. This results in the housing  850  sliding away from engagement with the bronchial isolation device  115  so that the bronchial isolation device  115  is eventually entirely released from the housing  850  and implanted in the bronchial passageway at the target location L, as shown in  FIG. 11B . 
   During actuation of the actuation handle  830 , the outer shaft  820  can undergo tension and the inner shaft  825  undergo compression due to the relative movement of the shafts and possible friction against the proximal movement of the outer shaft  820 . This can result in an axial shortening of the inner shaft  825  and an axial lengthening of the outer shaft  820 . In order to compensate for this and to allow the device  115  to be fully ejected from the housing  850 , the flange  910  can be configured to over-travel a distance Y beyond the distal end of the housing  850 , as shown in  FIG. 11B . The over-travel of the flange  910  beyond the housing&#39;s distal end can create a potential problem during withdrawal of the delivery catheter  110 , particularly in situations where the delivery catheter  110  is deployed in a location that requires its distal end to bend at an acute angle.  FIG. 12  shows such a situation, where the bronchial isolation device  115  is deployed at a location in the bronchial tree  220  that requires the delivery catheter  110  to bend at an acute angle with the flange  910  withdrawn entirely from the housing  850 . In such situations, the flange  910  can catch on the tissue of the bronchial wall at a location  1210  inside the bend as the operator pulls the catheter  110  out of the bronchial passageway. This can make it difficult for an operator to remove the delivery catheter  110  from the bronchial passageway and can risk possible damage to the tissue if the operator continues to pull while the flange is caught on the bend. 
   This problem can be overcome by limiting the travel of the flange  910  relative to the housing  850  such that the flange  910  cannot move outward of the distal end of the housing  850 . One way this can be accomplished is by limiting the travel of the inner shaft  825  at the distal end of the catheter  110 .  FIG. 13  shows a cross-sectional view of the distal region of the catheter, showing the inner shaft  825  axially disposed in the outer shaft  820 . As mentioned, the flange  910  is attached to the inner shaft  825  and the housing  850  is attached to the outer shaft  820 . The inner shaft  825  has a step  1405  and the housing  850  or outer shaft  820  has a stop or ledge  1410 . The step  1405  is spaced from the ledge  1410  when the flange  910  is fully withdrawn in the housing  850 . As the outer shaft  820  moves in the proximal direction, the step  1405  eventually abuts the ledge  1410 , which acts as a stop to limit any further proximal movement of the outer shaft  820  relative to the inner shaft  825 . As shown in  FIG. 14 , the flange  910  is positioned just at the distal end of the housing  850  when the stop position is reached. Thus, the flange  910  and housing  850  have a relative range of travel therebetween. 
   In one embodiment, the flange  910  is limited from being distally positioned at all past a distal edge of the housing. In another embodiment, the flange  910  can be distally positioned past the distal end of the housing only to the extent that the flange will not catch onto tissue during withdrawal of the delivery catheter. Thus, referring to  FIG. 11B , the distance Y is sufficiently small to prevent or greatly reduce the likelihood of bronchial wall tissue being caught or pinched between the flange  910  and the housing  850  during withdrawal of the delivery catheter  110 . This eliminates the possibility of the flange  910  catching or lodging on the bronchial tissue during removal of the delivery catheter  110 . 
   Actuation Handle 
   There is now described an actuation handle for the delivery catheter that can be used to slide the outer shaft  820  (and the attached housing  850 ) relative to the inner shaft  825  while maintaining the inner shaft  825  stationary relative to the handle.  FIG. 15  shows a side view of an actuation handle  1510 . In the illustrated embodiment, the actuation handle  1510  has an elongate shape suitable for grasping within an operator&#39;s hand. It should be appreciated, however, that the shape of the actuation handle  1510  can vary. The actuation handle  1510  includes an actuation member, such as a slidable actuation slider  1515 , that can be actuated to slide the outer shaft  820  relative to the inner shaft  825  (the inner shaft is not shown in  FIG. 15 ) during ejection of the bronchial isolation device  115 . The actuation member can be positioned on the handle  1510  such that an operator can grasp the handle with a single hand and also move the actuation member using a finger or thumb of the same hand. For example, in the embodiment shown in  FIG. 15 , the slider  1515  is positioned along the side of the actuation handle  1510  so that the operator&#39;s thumb can be used to move the slider  1515 . Other configurations can be used. 
     FIG. 16  shows a cross-sectional view of the actuation handle  1510 , which includes an actuation system for moving the outer shaft relative to the handle. In one embodiment, the actuation system comprises a rack and pinion system for effecting movement of the outer shaft  820  relative to the inner shaft  825 . The actuation slider  1515  is coupled to the actuation system. The actuation slider  1515  is slidably positioned inside an elongate slot  1605  in the actuation handle  1510 . A distal end of the actuation slider  1515  abuts or is attached to a first rack  1610  that is also slidably mounted in the elongate slot  1605 . The first rack  1610  has a first edge with teeth that mesh with corresponding teeth on a first pinion  1615 . The first pinion  1615  is engaged with a second pinion  1620  having teeth that mesh with a second rack  1625  mounted in an elongate slot  1628 . The second rack  1625  is attached to the outer shaft  820  of the delivery catheter  110  such that movement of the second rack  1625  corresponds to movement of the outer shaft  820 . That is, when the second rack slidably moves in the proximal direction or distal direction, the outer shaft  820  also moves in the proximal or distal direction, respectively. The inner shaft  825  is fixedly attached to the handle  1510 , such as by using adhesive or through a friction fit. The first rack, second rack, first pinion, and second pinion collectively form a rack and pinion system that can be used to transfer distal movement of the actuation slider  1515  to proximal movement of the outer shaft  820  while the inner shaft  825  remains stationary relative to the handle  1510 , as described below. 
   The actuation slider  1515  can be positioned in an initial position, as shown in  FIG. 16 . When the actuation slider  1515  is in the initial position, the flange  910  is fully withdrawn inside the housing  950  (as shown in  FIG. 13 ). In one embodiment, the actuation slider  1515  is at the proximal end of the handle when in the initial position, although it should be appreciated that the initial position can vary. When the actuation slider  1515  slidably moves in the distal direction (represented by the arrow  1630  in  FIG. 16 ) from the initial position, the rack and pinion system causes the outer shaft  820  to slidably move in the proximal direction (represented by the arrow  1635  in  FIG. 16 ), and vice-versa, while the inner shaft  825  remains stationary relative to the handle. More specifically, movement of the actuation slider  1515  in the distal direction  1630  moves the rack  1610  in the distal direction, which drives the first pinion  1615  and which, in turn, drives the second pinion  1620 . The gearing between the second pinion  1620  and the second rack  1625  causes the second rack  1625  to move in the proximal direction  1635  through the slot  1628 . As mentioned, the second rack  1625  is attached to the outer shaft  820  so that the outer shaft  820  moves in the proximal direction  1635  along with the second rack  1625 . During such movement, a distal region of the outer shaft  820  slides into the handle  1510 . While this occurs, the inner catheter  825  (which is fixed to the handle  1510 ) remains stationary relative to the handle  1510  while the outer shaft  820  moves. Thus, when the operator moves the slider  1515  in the distal direction  1630 , the outer shaft  820  (and the attached housing  850 ) slides in the proximal direction, with the inner shaft  820  and flange  910  remaining stationary relative to the handle. The handle can be fixed relative to the patient such that the handle, inner shaft, flange and bronchial isolation device remain fixed relative to the patient during ejection of the bronchial isolation device from the housing. 
   The gear ratio between the first pinion  1615  and second pinion  1620  can be varied to result in a desired ratio of movement between the actuation slider  1515  and the outer catheter  820 . For example, the first pinion  1615  can have a larger diameter than the second pinion  1620  so that the outer shaft  820  (and the attached housing  850 ) are withdrawn in the proximal direction at a slower rate than the actuation slider  1515  is advanced in the distal direction. The gear ratio can also be varied to reduce the force required to move the actuation slider  1515  and thereby make it easier for an operator to control ejection of the bronchial isolation device  115  from the housing  850 . The ratio between the pinions can be altered to make the withdrawal of the outer shaft faster, slower, or the same speed as the actuation slider movement. In one embodiment, the rack and pinion system is configured such that a 2:1 force reduction occurs such that the actuator slider moves about twice the distance that the outer shaft  820  is moved. For example, if the slider is moved an inch in the distal direction, then the outer shaft and the attached housing moves about half an inch in the proximal direction, and vice-versa. 
   The handle  1510  can include a safety lock that retains the actuation slider  1515  (or any other type of actuation member) in the initial position until the operator applies a force to the actuation slider sufficient to disengage the safety lock. The safety lock prevents inadvertent deployment of the bronchial isolation device either by inadvertent movement of the actuation slider in the distal direction or by inadvertent movement of the outer shaft  820  in the proximal direction relative to the handle. Inadvertent proximal movement of the outer shaft  820  can possibly occur when the delivery catheter  110  is being advanced into the patient&#39;s trachea, which can cause resistance to be applied to the outer shaft  820  by an anesthesia adaptor valve, endotracheal tube, or the lung. 
   In one embodiment, the safety lock comprises one or more magnets positioned in the actuation handle  1510 .  FIG. 17  shows a partial, cross-sectional view of the proximal end of the handle  1510  with the actuation slider  1515  positioned distally of the initial position. A first magnet  1710  is located on the handle  1510  near the initial location of the actuation slider  1515 . A second magnet  1715  is located on or in the actuation slider  1515 . The magnets  1710 ,  1715  are oriented such that an attractive magnetic force exists therebetween. When the actuation slider  1515  is in the initial position, the magnetic force between the magnets  1710 ,  1715  retains the actuation slider  1515  in the initial position until the operator applies a force to the slider  1515  sufficient to overcome the magnetic force and move the slider  1515  out of the initial position. 
   It should be appreciated that configurations other than magnets can be employed as the safety lock. One advantage of magnets is that the attractive force between the magnets  1710 , 1715  automatically increases as the actuation slider moves toward the initial position. If the actuation slider happens to be out of the initial position when the bronchial isolation device is loaded into the housing  850 , the actuation slider  1515  is driven back toward the initial position as the bronchial isolation device is loaded into the housing  850 . The magnetic attraction between the first and second magnets  1710 , 1715  automatically engages the safety lock when the actuation slider  1515  moves into the initial position. 
   The safety lock can include an additional feature wherein the operator must depress the actuation slider  1515  in order to disengage the slider from the initial position. As shown in  FIG. 17 , the slot  1605  in the actuation handle  1510  has an opening  1712 . The actuation slider  1515  moves outward and sits in the opening  1712  when in the initial position. The operator must depress the slider  1515  to move the actuation slider  1515  out of the opening in order to disengage the slider from the initial position and slide the actuation slider  1515  in the distal direction. 
   Adjustment of Handle Position Relative to Bronchoscope 
   As discussed above, according to the transcopic delivery method, the bronchoscope  120  (shown in FIGS.  1 , 6 , 7 ) is used in deploying the delivery catheter  110  into the bronchial passageway. Pursuant to this method, the delivery catheter  110  is inserted into the working channel  710  of the bronchoscope  120  such that the delivery catheter&#39;s distal end is aligned with or protrudes from the distal end of the bronchoscope  120 . The bronchoscope  120 , with the delivery catheter  110  positioned as such, is then inserted into the bronchial passageway via the patient&#39;s trachea such that the distal end of the delivery catheter is positioned at a desired location in the bronchial passageway, as shown in  FIG. 1 . It should be appreciated that the delivery catheter  110  can be inserted into the bronchoscope  120  either before or after the bronchoscope has been inserted into the bronchial passageway. 
     FIG. 18  shows an enlarged view of the distal region of the bronchoscope  120  with the delivery catheter&#39;s distal end (including the housing  850 ) protruding outward from the working channel  710 . The bronchial isolation device  115  is positioned within the housing  850 . The bronchial isolation device  115  is a distance D from the distal end of the bronchoscope  120 . Once the bronchoscope and delivery catheter are in the patient, the operator may desire to adjust the distance D to fine tune the location of the bronchial isolation device  115 . However, it can also be desirable or even required to hold the actuation handle  1510 , and thus the inner shaft  825 , stationary relative to the bronchoscope  120 . This way, the bronchoscope  120  can be fixed relative to the patient&#39;s body, thereby keeping the bronchial isolation device  115  fixed relative to the target location in the bronchial passageway. 
     FIG. 19  shows another embodiment of the actuation handle, referred to as actuation handle  1910 , that can be used for transcopic delivery and that can be fixed relative to a bronchoscope while also allowing for adjustments in the distance D of  FIG. 18  once the delivery device is positioned in the bronchoscope. The actuation handle  1910  includes an actuation member in the form of a button  1915  that can be depressed in the distal direction to move the outer shaft  820  of the delivery catheter in the proximal direction. The handle includes an adjustment mechanism that is used to adjust the position of the handle relative to the bronchoscope. The adjustment mechanism comprises an elongated bronchoscope mount  1920  that extends outwardly from the distal end of the actuation handle  1910  and extends at least partially over the catheter outer shaft  820  such that the outer shaft can slide freely within the bronchoscope mount  1920 . The bronchoscope mount  1920  extends outward from the handle a distance A. The bronchoscope mount  1920  is slidably moveable into or out of the handle  1910  such that it can be pushed into or pulled out of the handle  1910  along the axis of the mount  1920  in order to adjust the distance A. In one embodiment the bronchoscope mount  1920  is biased outward, for example with a spring, so that its tendency is to be fully extended outward from the handle  1910 . A locking mechanism includes a lock, such as a lever  1925 , that can be depressed to lock the bronchoscope mount  1920  relative to the handle  1910  when the distance A is adjusted to a desired amount, as described below. Once the distance A is at a desired amount, the operator can lock the bronchoscope mount  1920  relative to the handle to fix the bronchoscope mount  1920  relative to the handle  1910 . 
   With reference to  FIG. 20 , the bronchoscope mount  1920  has a size and shape that is configured to sit within the entry port  135  of the bronchoscope working channel. In use, an operator can insert the bronchoscope mount  1920  into the entry port  135  such that it abuts and sits within the entry port  135 . In this manner, the actuation handle  1910  is fixed relative to the bronchoscope  120  with the catheter&#39;s distal end protruding a distance D from the bronchoscope&#39;s distal end (as shown in  FIG. 20 ). The operator can then adjust the distance A by moving the bronchoscope mount  1920  into or out of the handle  1910 , such as by pushing on the handle  1910  to decrease the distance A. By virtue of the outer and inner catheter shafts&#39; attachment to the handle, adjustments in the distance A will correspond to adjustments in D. That is, as the operator decreases the distance A ( FIG. 20 ), the catheter slides deeper into the bronchoscope so that the distance D ( FIG. 18 ) increases, and vice-versa. 
   Once the desired distance A has been achieved, the bronchoscope mount  1920  is locked by depressing the lever  1925 . Thus, by adjusting the distance A, the operator also adjusts the distance D (shown in  FIG. 18 ) between the distal end of the bronchoscope  120  and the bronchial isolation device  115 . This can be helpful where different brands or types of bronchoscopes have different length working channels. It also allows the operator to fine-tune the position of the housing  850  and bronchial isolation device in the bronchial passageway without moving the bronchoscope. Other mechanisms for locking the movement of the bronchoscope mount  1920  are possible such as depressing and holding the lever  1925  to release the movement of the bronchoscope mount  1920 , repositioning the bronchoscope mount  1920 , and releasing the lever  1925  to lock the bronchoscope mount  1920  in place. 
   Catheter Sheath 
   As discussed above, during use of the delivery catheter  110  it can be desirable to fix the location of the inner shaft  825  (and thus the bronchial isolation device in the housing  850 ) relative to the patient&#39;s body while proximally withdrawing the outer shaft  820  and the housing  850  relative to the bronchial passageway to eject the bronchial isolation device, as shown in  FIGS. 11A and 11B . Given that the outer shaft  820  moves proximally relative to the bronchial passageway during the foregoing process, the outer shaft  820  can encounter resistance to proximal movement due to friction with devices or body passageways in which the delivery device is positioned. For example, the outer surface of the outer shaft  820  can encounter frictional resistance against an anesthesia adaptor through which the outer shaft is inserted. The anesthesia adapter is a fitting that permits the bronchoscope and delivery catheter to be inserted into the lung without leakage of ventilated oxygen, anesthesia gases, or other airway gases. The adapter typically has a valve through which the delivery catheter or bronchoscope is inserted. The valve seals against the outer surface of the outer shaft  820  to prevent air leaks. This seal can provide resistance against proximal movement of the outer shaft  820  during ejection of the bronchial isolation device from the housing  850 . Such resistance to proximal movement of the outer shaft  820  is undesirable, as it can result in the bronchial isolation device  115  being deployed in a location distal of the target location in the bronchial passageway. 
     FIG. 21  shows an embodiment of the delivery catheter  110 , which includes a deployment sheath  2110  that reduces or eliminates the resistance to proximal movement of the catheter outer shaft  820  during ejection of the bronchial isolation device  115 . The deployment sheath  2110  is a sheath having an internal lumen in which the outer shaft  820  is slidably positioned. The sheath  2110  is fixed at a proximal end  2112  to the actuation handle  815 .  FIG. 21  shows the actuation handle  815 , although the sheath  2110  can be used with any type of handle. Furthermore, it should be appreciated that the sheath  2110  is not limited to use with delivery catheters that deploy bronchial isolation devices, but can rather be used with various types of catheters. For example, the sheath configuration can be used in combination with catheters suitable for use in venous, arterial, urinary, billiary, or other body passageways. The sheath  2110  extends over the outer shaft  820  a distance X. The distance X can vary. In one embodiment, the distance X is long enough to extend to locations where the outer shaft is likely to encounter frictional resistance to movement, such as at the anesthesia adapter, if present. However, when used with a delivery catheter having a housing  850 , the distance X is such that the distal end of the sheath does not interfere with the housing  850  being fully withdrawn in the proximal direction. 
   The sheath  2110  can have a very thin wall to minimize its contribution to the overall diameter of the delivery catheter  110 . In one embodiment, the sheath  2110  has a wall thickness in the range of approximately 0.002 inches to approximately 0.004 inches. The sheath  2110  is manufactured of a material that is lubricous to minimize resistance to the outer shaft  820  sliding inside the sheath  2110 . The sheath material also has a stiffness that resists crumpling when a compressive load is placed along the length of the sheath (such as when the sheath is possibly pinched or grabbed to fix its position relative to the anesthesia adapter during ejection of the catheter from the housing, as described below). The compressive forces can come from the possibility that the outer shaft is pinched when the sheath is pinched, and thus when the handle is actuated and the outer shaft starts to move towards the handle, the sheath is compressed]. The sheath  2110  can be manufactured of various materials, such as, for example, polyimide, Teflon doped polyimide, PolyEtherEtherKetone (PEEK), etc. 
   In use, the delivery catheter  110  is positioned in the patient&#39;s lung through the trachea, such as described above. This can involve the delivery catheter  110  being positioned through a device such as a bronchoscope or through an anesthesia adapter  2210 , such as shown in the partial view of  FIG. 22 . The sheath  2110  is located between the anesthesia adapter  2210  and the outer shaft  820  (not shown in  FIG. 22 ) such that the sheath  2110  provides a lubricous shield between the outer shaft  820  and the anesthesia adapter. Thus, the outer shaft  820  can be proximally moved using the actuation handle without the outer shaft  820  encountering frictional resistance from contact with the anesthesia adapter (or any other object or device in which the sheath and outer shaft are positioned). If desired, the operator can grab or pinch the catheter  110  (as represented by the arrows  2215  in  FIG. 22 ) through the sheath  2110  at the entrance of the anesthesia adapter  2210  to fix the location of the sheath  2110  (and thus the location of the handle and the inner shaft) relative to the patient and/or anesthesia adaptor. As the sheath  2110  is made of a relatively rigid and lubricous material, the outer shaft  820  is free to slide through the sheath in the proximal direction as the sheath is grabbed. 
   Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.