Abstract:
A pneumatic chest compression vest is disclosed for the purposes of clearing the lungs of mucus and producing quality sputum samples for analysis. The vest is comprised of a first portion that has an air bladder mounted on its inner surface that applies a compressive force to the region of the chest that encompasses the lungs. The vest is removably adjustable and extends around a patient to hold the vest in the correct position for fitting and during treatment.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation-in-part of U.S. patent applications Ser. No. 09/387,319 now abandoned, “Pneumatic Chest Compression Vest with Front Panel Bib;” Ser. No. 09/387,339, “Chest Compression Vest with Connecting Belt,” issued as U.S. Pat. No. 6,471,663; and Ser. No. 09/387,312, “Method and Apparatus for Inducing Sputum Samples for Diagnostic Evaluation,” issued as U.S. Pat. No. 6,379,316; which all were filed on Aug. 31, 1999 and which are all assigned to the same assignee as the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to chest compression devices and in particular to a high frequency chest wall oscillator device. 
     Manual percussion techniques of chest physiotherapy have been used for a variety of diseases such as cystic fibrosis, emphysema, asthma, and chronic bronchitis, to remove the excess mucus that collects in the lungs. To bypass dependency on a caregiver to provide this therapy, chest compression devices have been developed to produce high frequency chest wall oscillation (HFCWO), the most successful method of airway clearance. In addition, these devices can be utilized for diagnosis and treatment of pulmonary disorders such as lung cancer, asthma, chronic obstructive pulmonary disease (COPD), tuberculosis,  Pneumocystis carinii  pneumonia (PCP), inflammation, and infection. 
     The device most widely used to produce HFCWO is The Vest™ airway clearance by the assignee of the present application. A description of the pneumatically driven system can be found in the Van Brunt et al. patent, U.S. Pat. No. 5,769,797, which is assigned to the same assignee as the present application. Another pneumatic chest compression device has been described by Warwick et al., U.S. Pat. No. 4,838,263. 
     Pneumatically driven HFCWO produces substantial transient increases in the airflow velocity with a small displacement of the chest cavity volume. This action produces a cough-like shear force and reduction in mucus viscosity that results in an upward motion of the mucus. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a pneumatic chest compression vest that loosens and helps remove mucus from a person&#39;s lungs or induces production of sputum samples for further diagnostic analysis. The vest is designed to focus the compressive force on the region of the chest that encompasses the lungs. 
     One aspect provides a pneumatic chest compression vest including a first portion having an outer surface and an inner surface, the first portion adapted to be positioned over a first part of a circumference of a torso of a patient, the first portion being substantially non-stretchable, a second portion adapted to be positioned over a second part of the circumference of the torso of the patient, the second portion substantially non-stretchable and non-inflatable, the first portion and second portion removably circumscribing the torso of the patient, an air bladder mounted on the inner surface of the first portion, the air bladder having at least one opening through which the air bladder is connectable to a source of oscillating pneumatic pressure, and wherein the air bladder is adapted to be positioned over a portion of the circumference of the torso of the patient. 
     Another aspect provides a pneumatic chest compression vest including a first portion and a second portion, the first portion and the second portion adapted to removably circumscribe a torso of a patient, the first portion and the second portion being substantially non-stretchable, an air bladder mounted on an inner surface of the first portion, the air bladder having at least one opening through which the air bladder is connectable to a source of oscillating pneumatic pressure, and a fitting and fastening system. The fitting and fastening system may include a plurality of adjustable fasteners adapted to adjust and fasten the vest about the torso of the patient, at least one handgrip attached to the vest, the handgrip adapted to ease placement of the adjustable fasteners, and a plurality of stiffeners attached to the vest, the stiffeners adapted to position the handgrip about the torso of the patient. 
     Another aspect provides a pneumatic chest compression vest including a first portion and a second portion adapted to be positioned about a circumference of a torso of a patient and first means for positioning, fitting, and removably fastening the first portion and the second portion about the torso of the patient. 
     Another aspect provides a pneumatic chest compression vest including a first portion and a second portion adapted to be positioned about a circumference of a torso of a patient, and second means for applying an oscillating pressure to lungs of a patient, the second means attached to the first portion and only partially circumscribing a torso of the patient. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a person wearing one embodiment of a pneumatic chest compression vest. 
         FIG. 2  is a front view of one embodiment of a pneumatic chest compression vest. 
         FIG. 3  is a back view of one embodiment of a pneumatic chest compression vest. 
         FIG. 4  is a side view of one embodiment of an air coupling connected to a hose. 
         FIG. 5  is a top view of one embodiment of a suspender. 
         FIG. 6  shows where a person&#39;s lungs are located relative to the pneumatic chest compression vest. 
         FIG. 7  is a graph illustrating the performance of one embodiment of a pneumatic chest compression vest. 
         FIG. 8  is a top view of a second embodiment of a pneumatic chest compression vest. 
         FIG. 9  is a top view of one embodiment of a removable air bladder. 
         FIG. 10  is a top view of a third embodiment of a pneumatic chest compression vest. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows pneumatic chest compression vest  10  of one embodiment of the present invention fitted onto patient P. Pneumatic chest compression vest  10  is shown with front panel  12 , belt  14  with belt holes  16 , air couplings  18 , suspenders  20 , hoses  22 , and pneumatic pressure generator  24 . Front panel  12  of pneumatic chest compression vest  10  covers from approximately the bottom of the patient&#39;s rib cage to near the patient&#39;s collar bone and extends over the front of the patient&#39;s chest to under the patient&#39;s arms. Belt  14 , which is attached to one side of front panel  12 , wraps around the patient&#39;s back and across front panel  12 . Pneumatic chest compression vest  10  is secured by aligning belt holes  16  with air ports (not shown) on front panel  12  so that air couplings  18  can insert through belt holes  16  and the air ports. Suspenders  20  are also attached to secure pneumatic chest compression vest  10  in place. One end of hoses  22  attaches to air couplings  18  and the other end attaches to pneumatic pressure generator  24 . Pneumatic pressure generator  24  provides the oscillating pressure to vest  10  to apply compressive force to the patient&#39;s chest. Pneumatic chest compression vest  10  and its operation will be described in more detail in subsequent figures. 
       FIG. 2  is a front view of pneumatic chest compression vest  10  laid flat. Front panel  12  is comprised of central bib portion  12   a,  side portions  12   b  and  12   c,  tab  34 , tab seams  36 , air ports  38 , and liner seam  40 . Belt  14 , which attaches to front panel  12  at belt seam  30 , contains belt holes  16  with slits  32 . 
     Pneumatic chest compression vest  10  wraps around the torso of patient P. Belt  14  of pneumatic chest compression vest  10  extends around the back of patient P and across the outer surface of front panel  12 . Belt  14  contains longitudinally positioned belt holes  16  each of which includes a slit  32 . Tab  34  is welded onto front panel  12  at tab seams  36  and inserts into one of the belt holes  16 . 
     Pneumatic chest compression vest  10  is secured in place by overlapping belt holes  16  with air ports  38  on front panel  12 . The distance between air ports  38  corresponds to a multiple of the distance between each belt hole  16 . In one embodiment, the diameter of belt holes  16  and air ports  38  is about 1.4 inches with belt holes  16  centered about 2 inches apart, and air ports  38  are centered about 6 inches apart. Tab  34  is welded to front panel  12  at tab seams  36  so that it aligns with air ports  38  on front panel  12  in such a way that as belt  14  wraps around patient P and extends across the outer surface of front panel  12 , tab  34  can insert into a belt hole  16 . When tab  34  is inserted into a belt hole  16 , corresponding belt holes  16  will align with air ports  38 . Once aligned, air couplings  18  can easily be snapped into belt holes  16  and air ports  38  (See FIG.  1 ). Depending on the circumference of the patient&#39;s torso, different belt holes  16  will align with tab  34  and air ports  38 . This allows adjustment of pneumatic chest compression vest  10  so that it fits securely around patient P. 
     Slits  32  may be about 0.2 inch long. Slits  32  allow ease of insertion of suspenders  20  into belt holes  16  (See FIG.  1 ). 
     Liner seam  40  extends along the perimeter of front panel  12  encompassing central bib portion  12   a,  which may have a height of about 11.75 inches but can be from about 9.0 to about 13.0 inches, and side portions  12   b  and  12   c,  which may have a height of about 7.75 inches but can be from about 6.0 to about 9.0 inches. 
       FIG. 3  is a back view of pneumatic chest compression vest  10  laid flat. Front panel  12  includes central bib portion  12   a,  side portions  12   b  and  12   c,  air ports  38  (in phantom), and liner seam  40 . A liner  50  is shown welded to the inner surface of front panel  12  along liner seam  40 . Belt  14 , belt holes  16  with slits  32 , belt seam  30 , and tab  34  (in phantom) are shown and were described in FIG.  2 . 
     Liner  50  may be made of an elastic material such as 4 mil polyethylene, and the remaining parts, except air couplings  18 , are made of an inelastic material such as 8 mil polycarbonate or 20 mil polyethylene. These materials are relatively inexpensive and can be easily incinerated, producing no toxic emissions and little particulate matter for disposal. Liner  50  mounted onto front panel  12  defines an air bladder that is about 21 inches wide. 
     In operation, the air bladder is inflated via air ports  38  against the chest of patient P to apply a compressive force to the patient&#39;s lungs. Side portions  12   b  and  12   c  allow the air bladder to extend under the arms of patient P. Thus, the air bladder also compresses the sides of the torso that cover the patient&#39;s lungs. The combination of a generally rigid outer surface and flexible bladder prevents the vest from taking on a circular shape when the air bladder is inflated. Instead, inflating the air bladder forces the chest to change shape so that most of the motion during compression is inward, and the outward force is minimized. This increases the efficiency of the system. The volume of the air bladder is also reduced over the prior art vests, which makes the system more efficient in terms of applying the sane volume of air over a smaller surface area so that the magnitude of force necessary for deep sputum induction is achieved. 
     Pneumatic chest compression vest  10  is suitable for typical pressure requirements of about 0.5 to about 1.0 P.S.I., and can operate for about 30 to about 45 minutes during an oscillatory chest compression treatment. It may last longer for other less stringent applications. 
       FIG. 4  shows a side view of air coupling  18  connected to hose  22 . Air coupling  18  includes head  18   a,  neck  18   b,  and body  18   c  (shown partially in phantom). A portion of hose  22  is shown partially enclosing body  18   c  of air coupling  18 . 
     In one embodiment, air coupling  18  is made of aluminum with a height of about 3.25 inches. The height of head  18   a  is about 0.85 inches, neck  18   b  is about 0.75 inches, and body  18   c  is about 1.65 inches and is removably attached to neck  18   b.  Also, hose  22  is angled about 90 degrees at the end that connects to air coupling  18 . 
     Head  18   a  is beveled with the diameter increasing from about 1.30 inches to about 1.40 inches. The inside diameter of head  18   a  is about 1.15 inches. Neck  18   b  has a diameter of about 1.36 inches. Body  18   c  has a diameter of about 1.50 inches with an inside diameter of about 1.20 inches. The inside diameter of air coupling  18  increases from head  18   a  to body  18   c.    
     The operation of air coupling  18  is discussed in reference to other parts of pneumatic chest compression vest  10  that are not shown. Head  18   a  snaps through belt holes  16  and air ports  38  into the air bladder. Neck  18   b  remains within front panel  12  and belt  14  to secure pneumatic chest compression vest  10  around patient P. Hose  22  connects to and partially overlaps body  18   c,  which is not connected to neck  18   b  at this point. Body  18   c,  when connected to neck  18   b,  remains on the external side of pneumatic chest compression vest  10 . Thus, air coupling  18  has dual functions-to secure pneumatic chest compression vest  10  and provide a coupling to attach hose  22 . With hose  22  essentially hanging parallel to front panel  12 , hose  22  hangs in a manner which keeps air coupling  18  from pulling outward on pneumatic chest compression vest  10 . 
       FIG. 5  shows suspender  20  laid flat. Suspender  20  is comprised of strap  20   a  and serrated ends  20   b  that include serrations  20   c.    
     In one embodiment, the length of suspender  20  is about 35.0 inches. Serrated ends  20   b  are about 7 inches long, and each includes about 6 approximately 1 inch long serrations  20   c.  Strap  20   a  has a width of about 1.1 inches. Serrations  20   c  extend out to about 1.6 inches. 
     In operation, suspenders  20  extend from the front to the back of pneumatic chest compression vest  10  and insert into two of the belt holes  16  on the front and another pair of belt holes  16  in the back. Serrations  20   c  allow suspenders  20  to be adjusted to the proper length for a secure fit. In one embodiment, suspenders  20  are crossed in front of patient P to minimize movement or slippage of pneumatic chest compression vest  10  during treatment (See FIG.  1 ). 
       FIG. 6  illustrates how pneumatic chest compression vest  10  is positioned with respect to the patient&#39;s lungs and skeletal structure. An outline of front panel  12  with top edge  60  and bottom edge  62  of pneumatic chest compression vest  10  indicates the region of the patient&#39;s chest that is covered. 
     In operation, front panel  12  preferably covers the region of the torso that encases the lungs of patient P. Top edge  60  is positioned near the patient&#39;s collarbone, and bottom edge  62  is positioned near the bottom of the patient&#39;s rib cage. Compression on the abdomen is minimized, and top edge  60  reaches up to the upper lobes of the lungs to facilitate mucus removal in the upper lobes. Thus, the improved design increases the efficiency of the system to obtain sufficient sputum induction and mucus mobilization. 
       FIG. 7  shows the results of a comparison done between one embodiment (new vest), an embodiment without the bib section of central bib portion  12   a  (new vest w/o bib), an embodiment positioned backwards (new vest backwards), and a prior art vest (old vest).  FIGS. 2 and 3  provide a view of the bib section of central bib portion  12   a.  The bib section is the part of front panel  12  that compresses the upper lobes of the lungs. Peak expiratory volume (peak volume) was measured on a single subject with each variation over an oscillatory frequency range between 5 and 20 Hertz. The subject was fitted with a vest and given a mouthpiece with a hose attached to a volume chamber. The volume chamber was equipped with a sensor that measured changes in oscillatory volume. Expiratory volumes were measured with each vest variation tested at 5, 10, 15, and 20 Hertz. The graph illustrates that one embodiment with the front panel over the patient&#39;s chest and the bib portion extending to about the collarbone produces higher peak volume of airflow. The high peak volume of airflow corresponds to an increased force asserted on the mucus that results in increased mobilization. 
       FIG. 8  shows a second embodiment of a pneumatic chest compression vest  110 . Vest  110  has a first portion  112  and a second portion  114 . The first portion  112  and the second portion  114  each have an inner surface  180  and an outer surface (reverse side not shown). The first portion  112  has an air bladder  116 . The air bladder  116  may be formed as a separate part as shown, or may be integral with the first portion  112 . (See FIG.  9 ). The first portion  112  and second portion  114  are made of a flexible non-stretchable material, such as a polyester material, such as Hydra-tuff 600 denier polyester with a 7 ounce per square yard PVC laminate. The material is substantially non-stretchable so that the first portion and the second portion remain substantially unchanged in general shape when subjected to a source of oscillating pneumatic pressure. 
     The first portion  112  and air bladder  116  are adapted to be positioned in front of a person&#39;s torso, however, the first portion  112  may also be positioned in back of the torso. The first portion  112  has two bladder pockets  118   a,    118   b  for securing the air bladder to the inner surface  180  of the first portion. Optionally, a single bladder pocket, or additional bladder pockets may be used to secure the air bladder to the first portion. 
     The vest  110  includes a fitting and fastening system  160  for custom fitting of the vest to the patient and for ease in fastening the vest about a person&#39;s torso. The first portion  112  and second portion  114  each are adapted to partially circumscribe the torso of a patient. The air bladder is adapted to be positioned over a portion of the torso, such as the front, the front and sides, the back, the back and sides, or less than 75% of the circumference of the torso. 
     The fitting and fastening system  160  includes a two-part vest  112 ,  114 , hook and loop fasteners  120 , handgrips  130 , and stiffeners  140 . The two part vest comprises a first portion  112  and a second portion  114 . The first portion  112  is adapted to be positioned on the front of a person&#39;s torso and the second portion is adapted to be positioned on the back of a person&#39;s torso. The first and second portions each have two shoulder straps  122 , a mid portion  124  (to allow room for the arms) and a bottom portion  126 . 
     Hook and loop fasteners  120  are located on the shoulder straps  126  with the loop fasteners  120 a on the first portion  112  and the hook fasteners  120   b  on the second portion  114 . Optionally, the hook  120   b  and loop  120   a  fasteners could be reversed or other fasteners could be used to secure the shoulder straps  122  in position. The loop portion  120   a  of the fastener extends the length of the shoulder strap  122  allowing adjustment of the length of the shoulder straps. 
     Hook and loop fasteners  120  are located on the bottom portion  126  of the first portion  112  and the bottom portion  126  of the second portion  114 . The bottom portions  126  of the first and second portions are adapted to fasten together with hook and loop fasteners to circumscribe the torso of the patient. Loop fasteners are positioned on the ends  128  of the second portion  114  and hook fasteners are located on the front (hidden side) of the bottom portion  126  of the first portion  112 . Optionally, the hook and loop portions could be reversed or other fasteners could be used to secure the first and second portions in position. Hook and loop fastening material extends over substantially the entire bottom portion of the first portion allowing adjustment of the circumference of the vest. 
     Handgrips  130  are positioned at the end  128  of the bottom portions  126  of the second portion  114 . The handgrips  130  provide for easier fitting and securing of the vest. The handgrips  130  extend from the edge  128  of the of the bottom portion. The handgrips  130  are comprised of flexible material such as one inch looped polypropylene strapping material. The handgrips  130  extend parallel to the bottom edge  132  of the second portion, or optionally at an angle upwardly or downwardly from parallel. 
     Stiffeners  140  are attached to the vest at various positions to provide a stiffener system  142 . The stiffener system  142  includes vertical stiffeners  140   a  and horizontal stiffeners  140   b.  Optionally, vertical or horizontal stiffeners may be used or other positions, such as diagonal may be used, either separately, or in combination. The stiffeners  140  allow the vest to be at least temporarily formed by hand to a particular shape. The stiffeners  140  are comprised of a rigid formable material, such as metal, such as 16 Gauge insulated copper wire. Optionally, other rigid formable materials, such as plastic may be used. The stiffeners  140  may be permanently attached to the vest, such as by sewing into the hem, such as along the bottom edge  132  of the vest, or optionally, the stiffeners can be removably attached to the vest by locating the stiffener  140  in a pocket  144  with an opening  146  through which the stiffener may be removed. The stiffeners provide at least temporary rigidity to portions of the vest. The rigidity of the vest allows the vest to be more easily positioned about the torso for fastening. For example, stiffeners are positioned in the shoulder straps  122  so that the first portion and second portion may be positioned on the shoulders. Secondly, the stiffeners  140  are positioned along the bottom edge  132  of the second portion so that the bottom portion may be formed around the torso. Thirdly, the stiffeners are positioned so that the handgrips  130  are positioned for easier reach, such as at the sides or in front of the torso. 
     The embodiment shown in  FIG. 8  has two vertical stiffeners in the second portion  114 , each extending from about 1 inch from the end  150  of the shoulder straps along the length of the shoulder straps to the bottom edge  132  of the second portion. The embodiment also has two vertical stiffeners in the first portion extending along the outside edge of the bottom portion. The embodiment has two horizontal stiffeners, a horizontal stiffener  140   b  along the bottom edge  150  of the first portion  112  and second horizontal stiffener along the bottom edge  132  of the second portion  114 . 
       FIG. 9  shows one embodiment of an air bladder  116 . The bladder  116  has a front panel  170  and a back panel  172  (hidden) sewn together at the outside edge  174 . The front panel and back panel are a flexible, non-stretchable airtight material such as 600 denier polyester with 7 ounces per square yard PVC laminate. However, other substantially airtight inflatable materials, such as rubber may also be used. The front panel has two openings for two connectors, similar to those shown in FIG.  4 . 
     The bladder may be sized and shaped such that the bladder  116  covers substantially the entire front lung area as shown in FIG.  6 . The bladder  116  may be sized and shaped such that the bladder covers the bottom portion  126  and the mid portion  124  of the first portion  112  (See FIG.  8 ). Optionally, the bladder  116  covers only the bottom portion  126 . 
       FIG. 10  shows a third embodiment of a pneumatic chest compression vest  210 . Vest  210  has a first portion  212  and a second portion  214 . The first portion  212  and the second portion  214  each have an inner surface  280  and an outer surface (Reverse side not shown). The first portion  212  has an air bladder  216 . The air bladder  216  may be integral with the first portion, as shown, or formed out of separate panels as previously shown in FIG.  8 . The first portion and second portion are made of a flexible material, such as a polyester material with a PVC laminate, such as Hydra-tuff 600 denier polyester with a 7 ounce per square yard PVC laminate. The material is substantially non-stretchable so that the first portion and the second portion remain substantially unchanged in shape when subjected to a source of oscillating pneumatic pressure. 
     The first portion  212  including the air bladder  216  are adapted to be positioned in front of a person&#39;s torso, however, the first portion may also be positioned in back of the torso. The first portion has an integral bladder  216  formed to it by securing a second panel  218  to a portion of one side  217  of the first portion  212  forming an inner surface  280 . The second panel  218  is comprised of a flexible airtight material, such as PVC coated polyester material. The second panel  218  is secured to the first portion  212  in a pleated arrangement so that the air bladder  216  can expand to a larger volume. The first portion  212  and the second portion  214  each are adapted to partially circumscribe the torso of a patient. The air bladder is adapted to be positioned over a portion of the torso, such as the front, front and sides, back, back and sides, or less than about 75% of the circumference of the torso. 
     The vest  210 , like the previous embodiment also includes a fitting and fastening system  260  for custom fitting of the vest to the patient and for ease in fastening the vest about a person&#39;s torso. The first portion and second portion are adapted to removably circumscribe the torso. 
     The fitting and fastening system includes a two-part vest  212 ,  214 , hook and loop fasteners  220 , handgrips  230 , and stiffeners  240 . The two-part vest comprises a first portion  212  and a second portion  214 . The first portion  212  is adapted to be positioned on the front of a person&#39;s torso and the second portion  214  is adapted to be positioned on the back of a person&#39;s torso. The first and second portions each have two shoulder straps  216 , a mid portion  222  (to allow room for the arms) and a bottom portion  224 . The shoulder straps  216  of the second portion  214  are angled outwardly to allow easier attachment and better fit of the shoulder straps to the first portion. 
     Hook and loop fasteners  220  are located on the shoulder straps  216  with the loop  220   a  on the first portion  212  and the hook fasteners  220   b  on the second portion  214 . Optionally, the hook and loop portions could be reversed or other fasteners could be used to secure the shoulder straps in position. The loop portion  220   a  of the fastener extends substantially the length of the shoulder strap  216  allowing adjustment of the length of the shoulder straps. 
     Hook and loop fasteners  220  are located on the bottom portion  224  of the first portion  212  (on the reverse side) and the bottom portion  224  of the second portion  214 . The bottom portions  224  of the first and second portions are adapted to fasten together with hook and loop fasteners to circumscribe the torso of the patient. Loop fasteners  220   a  are positioned on the ends of the second portion  214  and hook fasteners are located on the front (reverse side) of the first portion  212 . Optionally, the hook and loop portions could be reversed or other fasteners could be used to secure the first and second portions in position. Hook and loop fastening material extends over substantially the entire bottom portion  212  of the first portion allowing adjustment of the circumference of the vest. 
     Handgrips  230  are positioned at the edge  232  of the bottom portions of the second portion. The handgrips  230  provide for easier fitting and securing of the vest. The handgrips  230  extend from the edge  232  of the of the bottom portion. The handgrips  230  are comprised of flexible material such as one inch looped polypropylene strapping material. The handgrips  230  extend downwardly from parallel of the bottom edge  234  of the second portion, or optionally at an angle upwardly or extending substantially parallel. 
     Stiffeners  240  are attached to the vest at various positions to provide a stiffener system  260 . The stiffener system  260  includes vertical stiffeners  240   a  and horizontal stiffeners  240   b.  Optionally, vertical or horizontal stiffeners may be used or other positions, such as diagonal may be used, either separately, or in combination. The stiffeners  240  allow the vest to be at least temporarily formed by hand to a particular shape. The stiffeners  240  are comprised of a rigid formable material, such as metal, such as 14 Gauge insulated copper wire. Optionally, other rigid formable materials, such as plastic may be used. The stiffeners  240  may be permanently attached to the vest, such as by sewing into the hem, such as along the bottom edge  234  or outside edges  232  of the vest, or optionally, the stiffeners can be removably attached to the vest by locating the stiffener in a pocket with an opening through which the stiffener may be removed. The stiffeners provide at least temporary rigidity to portions of the vest. The rigidity of the vest allows the vest to be more easily positioned about the torso for fastening. First, the stiffeners are positioned along the bottom edge of the second portion so that the bottom portion may be formed around the torso. Secondly, stiffeners are positioned along the outside edge  232  of the second portion and vertically in the middle of the second portion to provide rigidity for ease of fastening. Thirdly, the stiffeners are positioned so that the handgrips  230  are positioned for easier reach, such as at the sides or in front of the torso. 
     The embodiment shown in  FIG. 10  has four vertical stiffeners in the second portion, two vertical stiffeners extending from about 1 inch from the base of the shoulder straps to the bottom edge of the second portion and two vertical stiffeners extending substantially along the outside edge of the bottom portion. The embodiment has one horizontal stiffener along the bottom edge of the second portion. 
       FIG. 10  shows an integral air bladder  216 . Air bladder  216  is formed by a front panel  217  of the first portion and a second panel  218  sewn together at the outside edge  270  and horizontally approximately at the base  272  of the shoulder straps. The front panel  217  is a flexible, non-stretchable airtight material such as 600 denier polyester with 7 ounces per square yard PVC laminate. The second panel  218  is a flexible non-stretch airtight material such as 200 denier nylon material coated with 7 ounces per square yard PVC laminate. The second panel  218  is secured to the front panel  217  in a pleated pattern. The pleated pattern provides a larger more conforming air bladder. The material is overlapped approximately one inch every 6 inches creating approximately three horizontal pleats  274  and two vertical pleats  276 . The front panel has two openings for two connectors, such as those shown in FIG.  4 . 
     The bladder is sized and shaped such that the bladder covers substantially the entire front lung area as shown in FIG.  6 . The bladder is sized and shaped such that the bladder covers the bottom portion and the mid portion of the front portion. 
     In operation, one embodiment of the present invention provides a method of providing high frequency chest wall oscillation to a patient, the method including fitting on a patient a vest having a first portion with an air bladder so that the air bladder is positioned in contact with a limited portion of a torso of a patient that encompasses lungs of the patient; and supplying an oscillating pneumatic pressure to the air bladder so that pressure is applied by the air bladder to the lungs. The method optionally includes positioning the vest with stiffeners, adjusting a circumference of the vest with adjustable fasteners, placing the vest over a head of the patient, securing the vest in position with adjustable fasteners with the adjustable fasteners positioned at a point away from a center of a chest of the patient, or securing the vest with shoulder straps which extend over shoulders of the patient. 
     Another embodiment provides a method of providing chest wall oscillation to a patient including positioning a vest on a patient so that an air bladder carried on an inner surface of a first portion of the vest is located adjacent a chest of the patient and applying pneumatic pressure through the air bladder over an area on the chest of the patient from about a bottom of a rib cage to a collarbone. 
     Another embodiment provides a method of providing chest wall oscillation to a patient including positioning a vest carrying an air bladder so that the air bladder engages only a portion of a torso of a patient and applying pressure through the air bladder to the torso of the patient. 
     Another embodiment provides a method of providing high frequency chest wall oscillation to a patient including mounting on a patient a vest having a first portion with an air bladder so that the air bladder is positioned in contact with a region of a chest of a patient that encompasses lungs of the patient and supplying an oscillating pneumatic pressure to the air bladder so that pressure is applied by the air bladder to the lungs of the patient. 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.