Abstract:
An airway clearance combines a force multiplying percussor and a self-applicator assembly. The percussor has an anvil, a hammer, a coil, and a pulse generator. The anvil has a force receiving surface and a force delivering surface. The hammer also has a force-receiving surface and a force-delivering surface, and is attached to the anvil such that the hammer&#39;s force delivering surface and the anvil&#39;s force receiving surface are mechanically free to come together or move apart. When energized with an electrical current, the coil forces the hammer&#39;s force delivering surface and the anvil&#39;s force receiving surface to separate. The pulse generator supplies pulses of electrical current to the coil.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to airway clearance treatments. Specifically, the present invention is directed to a force-multiplying percussor and self-applicator system for airway clearance. A percussor is a medical device for supplying impulse forces to a patient&#39;s back or chest for the purpose of loosening and dislodging bronchial secretions in the lungs. A self-applicator is a strap that holds a percussor in a secure manner such that an individual can apply the percussor to their back without assistance from another person. 
       BACKGROUND OF THE INVENTION 
       [0002]    A percussor is a medical device for supplying impulse forces to a patient&#39;s back or chest for the purpose of loosening and dislodging bronchial secretions in the lungs. The present invention is of a system of straps to allow a person to properly apply a percussor against his or her own back. 
         [0003]    The type of percussor is based on the use of a solenoid in developing impulse forces for application to a patient&#39;s back or chest, A “solenoid”, as defined in the McGRAW-HILL, DICTIONARY OF SCIENTIFIC AND TECHNICAL TERMS, Fourth Edition, Sybil P. Parker, Editor in Chief, McGraw-Hill Book Company, New York, N.Y., 1989, s “a coil that surrounds a movable iron core which is pulled to a central position with respect to the coil when the coil is energized by sending current through it.” 
         [0004]    An example of this type of percussor is described in US. Pat. No. 4,512,339 as a device which energizes a coil to develop an impulse force for application to a patient and utilizes a compressed spring to return the movable iron core to its rest position. The designs of percussors of this type are unnecessarily complicated and inflexible with respect to theft use in treating patients and the adjustment of the operating parameters of the devices. 
         [0005]    The present invention avoids the complexities and inflexibilities of the prior art by utilizing a solenoid in a new and different way in generating impulse forces. The present invention utilizes the solenoid only for returning the movable iron core to its rest position. The patient--experienced impulse forces that result from the present invention are multiplied versions of the continuing force applied by a technician in using the invention. 
         [0006]    By the nature of such a percussor and human physiology, it is extremely difficult for individual to self-apply a percussor to their own back. The present invention makes it possible for an individual to hold a percussor against his or her own back so as to properly apply the impacting force for the purpose of loosening and dislodging bronchial secretions in the lungs. The person can self-apply the percussor so as to not require the services of a technician in using the percussor. 
         [0007]    Accordingly, there is a need for a self-applicator for an airway clearance device that addresses these needs. The present invention fulfills these needs and provides other related advantages. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention is directed broadly to a medical device for supplying impulse forces to a patient&#39;s back or chest for the purpose of loosening and dislodging bronchial secretions in the lungs. More particularly, the invention is a force-multiplying percussor and self-applicator system for airway clearance. The force-multiplying percussor comprises an anvil, a hammer, a con, and a pulse generator. The self-applicator comprises first and second straps joined at their respective ends. The first strap overlays and is substantially co-extensive with the second strap. A pouch for holding the percussor is disposed between the first and second straps. The self-applicator also comprises a pair of handles with one each attached to one of the respective ends of the first and second straps. 
         [0009]    In the percussor, the anvil is equipped with a force-receiving surface and a force-delivering surface which are rigidly connected together, the force-delivering surface being intended for contact with a patient&#39;s body. The hammer is also equipped with a force-receiving surface and a force-delivering surface, the hammer being oriented with respect to the anvil in such a way that the force-delivering surface of the hammer and the force receiving surface of the anvil are mechanically free to come together or move apart. 
         [0010]    The coil forces the force-delivering surface of the hammer and the force-receiving surface of the anvil to separate when the solenoid is energized with an electrical current. The puke generator supplies repeated electrical current pukes to the coil which causes repeated force-multiplied impulse forces to be applied to a patient&#39;s body via the force-delivering surface of the anvil whenever the technician applies a continuing force to the force-receiving surface of the hammer. 
         [0011]    In the self-applicator, the first strap is preferably longer than the second strap so as to define an open region between the two straps. The second strap has an application surface on one side. The application surface comprises a padded material and is configured so as to make physical contact with a user&#39;s back. The pouch is disposed in the open region. The pouch is attached to at least one and preferably both of the straps. 
         [0012]    The pouch comprises a closure mechanism. The closure mechanism is configured so as to securely hold the percussor. The closure mechanism comprises adjustable hook and loop straps configured so as to accommodate percussors of varying sizes. 
         [0013]    At least one of the pair of handles is attached to one of the ends of the first and second straps by an adjustable length harness. The other of the pair of handles is attached to the other of the ends of the first and second straps by a fixed length harness. 
         [0014]    A method for using the force-multiplying percussor and self-applicator system begins with the step of inserting the percussor into the pouch. The percussor is positioned in the pouch such that an anvil is oriented toward the second strap. A user then grasps each of the pair of handles in his/her hands. The user then self-applies the application surface of the second strap to his/her back. The percussor is turned on such that a force delivering surface of the anvil contacts the user&#39;s back through the application surface. 
         [0015]    The method further comprises the step of closing the closure mechanism on the pouch so as to securely hold the percussor in the pouch. The method also comprises the step of adjusting the length of the adjustable length harness on one of the pair of handles so that the user can comfortably perform the self-applying step. 
         [0016]    Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0017]    The accompanying drawings illustrate the invention. In such drawings: 
           [0018]      FIG. 1  is a perspective view of a first embodiment of the percussor of the present invention; 
           [0019]      FIG. 2  is a sectional view taken along line  2 - 2  of  FIG. 1  with the hammer shown in a neutral position relative to the anvil; 
           [0020]      FIG. 3  is a sectional view taken along line  2 - 2  of  FIG. 1  with the hammer shown fully-withdrawn from contact with the anvil; 
           [0021]      FIG. 4  is a perspective view of a second embodiment of the percussor of the present invention; 
           [0022]      FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 4  with the hammer shown in a neutral position relative to the anvil: 
           [0023]      FIG. 6  is a sectional view taken along line  5 - 5  of  FIG. 4  with the hammer shown in contact with the anvil; 
           [0024]      FIG. 7  is a schematic drawing illustrating the inputs and outputs of the pulse generator which supplies the driving current for the percussor; 
           [0025]      FIG. 8  is an elevated perspective view of the self-applicator of the present invention; 
           [0026]      FIG. 9  is an elevated perspective view of the self-applicator of the present invention illustrating insertion of a percussor; 
           [0027]      FIG. 10  is an exploded perspective view of the self-applicator of the present invention; 
           [0028]      FIG. 11  is an environmental view of the force multiplying percussor and self-applicator system of the present invention being self-applied by a user; 
           [0029]      FIG. 12  is a close-up cut-away view of the force multiplying percussor and self-applicator system of the present invention being self-applied by a user; 
           [0030]      FIG. 13  is a perspective view of a particularly preferred embodiment of a percussor of the present invention; 
           [0031]      FIG. 14  is a cut-away view of the particularly preferred embodiment of the percussor depicted in  FIG. 13 ; 
           [0032]      FIG. 15  is a partially dis-assembled view of the particularly preferred embodiment of the percussor of  FIG. 14 ; 
           [0033]      FIG. 16  is a cross-sectional view of the front wall of the particularly preferred embodiment of the percussor of  FIG. 14 ; 
           [0034]      FIG. 16   a  is an end view of the front wall of the particularly preferred embodiment of the percussor of  FIG. 14 ; 
           [0035]      FIG. 17  is a side view of the shaft and plunger of the particularly preferred embodiment of the percussor of  FIG. 14 ; and 
           [0036]      FIG. 18  is a cross-sectional view of the rear support bearing of the particularly preferred embodiment of the percussor of  FIG. 14 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]    The present invention is directed to a force-multiplying percussor and self-applicator system for airway clearance, the system being referred to generally by reference numeral  20 . The system  20  comprises a percussor  22  and a self-applicator  24 , all of which are illustrated in  FIGS. 1-12 . 
         [0038]    A first embodiment of the percussor  22  is shown in  FIGS. 1-3 . The percussor  22  of the present invention consists of a hammer  26  and an anvil  28  oriented with respect to one another such that the hammer  28  may impact the anvil  28 . The percussor  22  is configured to be placed on the back or chest of a patient with the anvil  28  in contact with the patient&#39;s body. Typically, a user holds the percussor  22  in place by gripping the hammer  26  with one hand, palm on top, and then turns on the power. The force continually applied by the user to the hammer  26  is converted by the percussor  22  into repeated force-multiplied impulses in which the force associated with each impulse is significantly greater than the force being applied by the user on a continuing basis. 
         [0039]    The details of the percussor  22  design are shown in the sectional views of  FIGS. 2 and 3 . The hammer  26  consists of a plastic structural member  30  attached to guiding member  32 . Guiding member  32  may be either metal or plastic and attaches to structural member  30  utilizing mating threaded regions (not shown), Coil  34  is embedded in structural member  30  as shown (assuming structural member  30  is a plastic material). 
         [0040]    The anvil  28  consists of ring  36  and platen  38  connected together by cylindrical guiding member  40 . Ring  36  has a rectangular cross-section and is made of a magnetic material such as iron. Guiding member  40  attaches to ring  36  by a press fit. Platen  38  is attached to guiding member  40  by means of a machine screw (not shown). The hammer  26  has a force receiving surface  42  and a force delivering surface  44 . The anvil  28  also has a force receiving surface  46  and a force delivering surface  48 . 
         [0041]    If there is no current flowing through coil  34 , hammer  26  is free to slide back and forth along guiding member  40  subject only to the constraints imposed by the combination of structural member  30  and guiding member  32 . Current flowing through coil  34  generates a magnetic field which exerts a force on ring  36  causing hammer  26  and anvil  28  to assume an extended position, i.e., the relative positions shown in  FIG. 3 . 
         [0042]    In operation, a user places the force delivering surface  48  of the anvil  28  against a patient&#39;s chest or back in the gentlest possible way and coil  34  is energized by a series of current pukes. When the coil  34  is energized, hammer  26  and anvil  28  will assume the extended position shown in HG.  3  and remain in that extended position for as long as the coil  34  is energized and the user does not apply a force to force-receiving surface  42  of the hammer  26 . 
         [0043]    Now assume that the user begins to apply a force (with their hand) to force-receiving surface  42  of the hammer  26  while the coil  34  is energized with a current puke. Nothing happens because the magnetic force from the energized coil  34  holding hammer  26  and anvil  28  in the extended position is greater than the force applied by the user. 
         [0044]    When the current puke to the coil  34  ends, the magnetic force holding the hammer  26  and anvil  28  in the extended position ends and any opposition to the force applied by the user to the force receiving surface  42  of the hammer  26  disappears, The force--delivering surface  44  of the hammer  26  then strikes the force-receiving surface  46  of the anvil  28  thereby delivering a considerably greater force to platen  38  than simply the force applied by the user&#39;s hand alone. The force delivering surface  48  of the anvil  28  translates the impact from the hammer  26  against the anvil  28  to the patient&#39;s chest or back with which it is in contact. The process repeats with each current puke supplied to coil  34 . 
         [0045]    The work expended by the user is the product F 1 d h , of the force F 1  applied by the user to the force receiving surface  42  of the hammer  26  and the distance d h  traveled by the hammer  26  before striking the anvil  28 . The user&#39;s work is converted into kinetic energy of the hammer  26 . This kinetic energy is dissipated when the hammer  26  strikes the anvil  28  and the anvil  28  depresses the patient&#39;s flesh, The kinetic energy is converted into potential energy associated with the depression of the patient&#39;s flesh and heat. The user&#39;s work is balanced by the work F p d p  expended by the patient&#39;s body which resists the anvil  28  with a force F p  over a distance d p . Thus, the effective force applied by the anvil  28  to the patient&#39;s body is given by F p =(d h /d p )F 1 . 
         [0046]    The ratio (d h /d p ) of the distance traveled by the hammer (d h ) to the distance traveled by the patient&#39;s flesh (d p ) is typically greater than three and consequently the percussor  22  described herein typically has a force-multiplying effect. For example, a user&#39;s force of  10  lbs is typically experienced as a force of 30 lbs or more by a patient. 
         [0047]    A second embodiment of the percussor  22  is shown in  FIGS. 4-6 . It also consists of a hammer  26  and an anvil  28 . The design details for the second embodiment are shown in the sectional views of FIGS,  5  and  6 , The hammer  26  consists of a plastic structural body  50  in which is embedded a core  52  made of a magnetic material such as iron. The anvil  28  consists of a plastic body  54  in which is embedded coil  34  which surrounds core  52  when the hammer  26  is inserted into the anvil  28 . 
         [0048]    As in the first embodiment, the hammer  26  has a force receiving surface  42  and a force delivering surface  44 , and the anvil  28  also has a force receiving surface  46  and a force delivering surface  48 , If there is no current flowing through the coil  34 , the hammer  26  is free to slide back and forth within the anvil  28  but limited in range by three pins (not shown) anchored into the curved wail of the anvil  28  and terminating in three vertical grooves (not shown) spaced 120 degrees apart in hammer  26 . When a current flows through the coil  34  it generates a magnetic field which exerts a force on core  52  causing hammer  26  and anvil  28  to assume the positions shown in Fig,  5 . 
         [0049]    In operation, the percussor  22  is paced against the back or chest of a patient with the force delivering surface  48  of the anvil  28  in contact with the patient&#39;s body, The user holds the percussor  22  in place by gripping the force receiving surface  42  of the hammer  26  with one hand, palm on top, and then turns on the power, As described above, the force continually applied by the user to the force receiving surface  42  of the hammer  26  is converted into repeated impacts of force on the patient&#39;s body through the force delivering surface  48  of the anvil  28  as current impulses pass through the coil  34 , Each time the current impulse through the coil  34  is ceased, the force delivering surface  44  of the hammer  26  impacts the force receiving surface  46  of the anvil  28 . Each such impact delivers the force through the anvil  28  to the force delivering surface  48 . The force associated with each impulse is significantly greater than the force being applied by the user to the force receiving surface  42  of the hammer  26  on a continuing basis, 
         [0050]    Let us again assume that a user places the percussor  22  against a patient&#39;s back in the gentlest possible way and coil  34  is energized by a series of current pukes. Hammer  26  and anvil  28  will assume the positions shown in HG.  5  and remain in those positions for as long as the technician does not apply a force to force-receiving surface  42 , Again assume that the technician begins to apply a force to force---receiving surface  42  while the coil  34  is energized with a current puke. Nothing happens because the magnetic force holding hammer  26  and anvil  28  in the relative positions of HG.  5  is typically greater than any force that can be manually applied by a user. 
         [0051]    When the current puke ends, the magnetic force opposing the force applied by the user disappears and the force-delivering surface  44  of the hammer  26  strikes the force-receiving surface  46  of the anvil  28  as shown in HG,  6 , The hammer  26  thereby delivers a considerably greater force to the patient&#39;s back with which the anvil  28  it is in contact, as discussed above. As long as the user maintains a force on the hammer  26 , the impacting process repeats with each current puke supplied to coil  34 , 
         [0052]    A schematic of the puke generator required to drive the coil  34  is shown in HG.  7 , it preferably operates with standard 120 V AC input power and has means for controlling the frequency and amplitude, i.e., widths and rate of repetition, of the output pukes. 
         [0053]    The self-applicator  24  consists of two substantially co-extensive straps having a pouch configured to accept and securely retain the percussor  22 .  FIGS. 8 through 10  illustrate the self-applicator  24  along with its various components. 
         [0054]    The self-applicator  24  has a pair of straps  56 ,  58  being substantially co-extensive with one overlaying the other. The respective ends of the straps  56   a ,  58   a  and  56   b ,  58   b  are stitched  60  together or joined by any securing means know to those skilled in the art. One of the straps  56  is preferably slightly longer that the other strap  58  such that when the ends of the first strap  56   a ,  56   b  are joined to the ends of the second strap  58   a ,  58   b , there is an open area  62  between the two straps  56 ,  58 . Preferably, the stitching  60  or other securing means is applied a second time  60   a  for added securement. 
         [0055]    A pouch  64  is disposed in the open area  62  between the straps  56 ,  58 . The pouch  64  may be in the form of a U-shaped pocket having a bottom  66 , upright sides  68   a ,  68   b  and an open top  70 . The pouch  64  in configured and designed to accept the percussor  22  through the open top  70  and securely retain the percussor  22  therein. Front and back edges  72   a ,  72   b  of the pouch  64  are in contact with inside surfaces  56   c ,  58   c  of the straps  56 ,  58 . At least one of the front and back edges  72   a ,  72   b  are attached to the inside surfaces  56   c ,  58   c  so as to securely retain the pouch  64  in the open area  62 . Preferably, both front and back edges  72   a ,  72   b  are attached to the inside surfaces  56   c ,  58   c.    
         [0056]    The pouch  64  also includes a closure mechanism  74  designed to cover the open top  70 . The closure mechanism  74  preferably comprises a pair of adjustable hook and loop straps  74   a ,  74   b . The straps  74   a ,  74   b  preferably have essentially their entire mating surfaces covered by hook and loop material, i.e., VELCRO®, whereby the respective straps  74   a ,  74   b  can be adhered to each other at any point along their length. The closure mechanism  74  can also comprise snaps, buttons, a zipper, or other commonly known methods of closure. 
         [0057]    A pair of handles  76 ,  78  are secured to the respective ends  56   a / 58   a ,  56   b / 58   b  of the straps  56 ,  58 . The ends  76   a ,  78   a  of the handles  76 ,  78  are preferably secured between the ends  56   a / 58   a ,  56   b / 58   b  of the straps  56 ,  58  when they are stitched  60  together. At least one of the straps  78  includes an adjustable length harness  80  so that the length of the handle  78  may be changed to accommodate users of different sizes. Each of the handles  76 ,  78  include respective grips  76   b ,  78   b  for a user  82  to grasp in each of his/her hands  84 . 
         [0058]    The second strap  58  includes an applicator surface  58   d  that is configured to contact the back  86  of a user  82  when the self-applicator system  20  is being applied. The application surface  58   d  is aligned with the inside surface  58   c  at the point where the pouch  64  is disposed or secured. The applicator surface  58   d  preferably comprises a soft, comfortable material that will not irritate a user&#39;s skin and can easily and smoothly move during use. The applicator surface  58   d  may even include padding to provide comfort to the user. 
         [0059]    The method of using the system  20  begins with arranging the self-applicator  24  on a surface such that the pouch  64  is oriented with the open top  70  pointing upwards. A user then inserts the percussor  22  into the open top  70  of the pouch  64 . The percussor  22  is positioned in the pouch  64  such that the anvil  28  on the percussor  22  is pointed toward the inside surface  58   c  of the second strap  58 . The closure mechanism  74  is secured around the percussor  22  so as to securely retain the percussor  22  in the pouch  64  in a manner that does not allow rotation, revolution or other similar movements during use. 
         [0060]    If necessary, the user  82  can adjust the length of the adjustable length harness  80  to make the system  20  more comfortable to use. The user  82  then grasps each of the handles  76 ,  78  in his or her hands  84  and self-applies the application surface  58   d  to his/her back  86 . As illustrated in  FIGS. 11 and 12 , the self-applicator  24  spans the user&#39;s back  86  with the user&#39;s hand  84  in front of his/her body, pulling the handles  76 ,  78  forward to apply force to the force receiving surface  42  of the hammer  26  and resultant pressure to the back  86 . The user  82  then turns on the percussor  22  with the results as described above. 
         [0061]    By moving ones hand  84  up/down and side/side, the user  82  can self-apply the percussor  22  to almost any area of his/her back  86 . By aligning the anvil  28  of the percussor  22  with the application surface  58   d , the user is able to keep the anvil  28  in contact with the user&#39;s back  86  without the need for a treatment technician or the aid of any other person. The user can also more easily self-apply the percussor  22  to those parts of his/her back  86  that are most beneficial for the loosening or dislodging of bronchial secretions in the lungs, rather than try and describe to another person where to apply the percussor  22 . 
         [0062]    Except for the applicator surface  58   d , described above, the self-applicator  24  and its various components are made from a sturdy, durable material such as nylon or similar polymer material. The goal in selecting a material is to make sure that the self-applicator  24  is comfortable for the user while still being durable enough to withstand the stresses of self-application and the movement of the percussor  22 . The grips  76   b ,  78   b  preferably comprise a soft, durable polymer material such as polyurethane, latex, or similar materials, molded to form hand grips  76   b ,  78   b.    
         [0063]      FIGS. 13 through 18  illustrate a particularly preferred embodiment of the percussor  90  of the present invention. From the outside, the percussor  90  consists of a rear cover or hand hold  92 , an anvil  94  and an intervening thermal shell  96 . Inside of the thermal shell  96  is a housing  98 , which encloses a solenoid  100 . The solenoid  100  comprises an internal shell  102  containing a central shaft  104  upon which is mounted a plunger  106 . The plunger  106  may be shaped as a cylinder with recessed cavities at its upper  106   a  and lower  106   b  ends. The plunger  106  may also be presented in other shapes so as to conform to adjacent parts as described below. The plunger  106  is made from magnetic material as the ring  36  or core  52  described above. A coil  108  surrounds the shaft  104  and plunger  106  and exerts magnetic forces thereon when energized. 
         [0064]    The bottom of the shell  102  contains a front wall  110  that includes an upward extending base  112  that generally matches the shape of the recess in the lower end  106   b  of the plunger  106 . The front wall  110  also includes a central opening  114  through which the shaft  104  extends. One end  104   b  of the shaft  104  protrudes through the front wall  110  and is connected to the anvil  94  by a screw  116  or similar securement mechanism. As the shaft  104  slides through the shell  102 , the anvil  94  follows. 
         [0065]    The top of the shell  102  contains a rear support bearing  118  secured thereto. The rear support bearing  118  has a lower surface that generally conforms to the shape of the recess of the upper end  106   a  of the plunger  106 . The rear support bearing  118  also includes a central opening  120  through which the shaft  104  extends. The central opening  114  of the front wall  110  and the central opening  120  of the rear support bearing  118  cooperate to keep the shaft  104  in straight line, oscillating movement through the shell  102 . 
         [0066]    The rear cover  92  provides a hand hold for a user to grasp the percussor  90 . In the terms of the previously described embodiment, the upper surface of the rear cover  92  provides a force receiving surface  122  of the hammer  124 . The force delivering surface  126  of the hammer  124  is located at the bottom of the housing  98 . The anvil  94  includes a force receiving surface  128  that receive impacts from the force delivering surface  126  of the hammer  124 . The anvil  94  also includes a force delivering surface  130 . These surfaces  122 ,  126 ,  128  and  130  interact as described above in the earlier embodiment. 
         [0067]    As shown in  FIG. 16   a , the front wall  110  includes set screw openings  132  around its perimeter. These set screw openings  132  are configured to receive set screws through the wall of the shell  102  so as to secure the front wall  110  thereto. The upper surface of the upward extending base  112  includes bumpers  134 . The bumpers  134  are configured to cushion the impact between the plunger  106  and the base  112  when the coil  108  is energized. This cushioning is only intended to make the impact less jarring or noise generating—it does not lessen the force of any impact. 
         [0068]    The thermal shell  96  is configured to insulate the user against heat generating by the oscillations of the solenoid  100  when the percussor  90  is in use. The thermal shell  96  provides an air gap  136  between the thermal shell  96  and the housing  98 . In addition, the rear cover  92  houses the pulse generator  138  as discussed above, as well as a cooling fan  140 . The pulse generator  138  is connected to the coil  108 . As the pulse generator  138  energizes the coil  108 , electricity is also supplied to the cooling fan  140 , which draws air through the housing  98  and out the exhaust vents  142  to provide additional cooling. 
         [0069]    The percussor  90  of this alternate embodiment may also be used with the self-applicator  24 . The percussor  90  may fit within the pouch  64  as described above. 
         [0070]    Although the system  20  has been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. The above-described disclosure is not intended to limit the scope of the invention. Accordingly, the scope of the present invention is determined only by the following claims.