Patent Publication Number: US-9833368-B2

Title: Person support apparatus with spring assistance for articulation

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit, under 35 U.S.C. §119(e), of U.S. Provisional Application No. 61/721,159, which was filed Nov. 1, 2012, and which is hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     Patient positioning is a significant concern in healthcare settings, particularly in circumstances wherein a patient supported by a person support apparatus is to be re-positioned from an elevated head of bed angle position of the person support apparatus to a horizontal position for administration of Cardiopulmonary Resuscitation (CPR). While several systems and methods have been developed to help re-position a person supported by a hospital bed, an opportunity exists for continued development in this area. 
     BRIEF SUMMARY 
     The present disclosure includes one or more of the features recited in the appended claims and/or the following features which, alone or in any combination, may comprise patentable subject matter. 
     One embodiment of a spring assist system for use with a person support apparatus, the person support apparatus may comprise a head support deck section supported by a supporting frame, the head support deck section configured to be variably inclined with respect to the supporting frame. The spring assist system may comprise a spring assembly. The spring assembly may comprise a spring configured to apply spring force assisting motion of the head support deck section from a first position to a second position wherein the head support deck section in the first position is at greater angle of inclination with respect to the supporting frame than in the second position and angular inclination of the head support deck section in the second position is greater than 0 degrees and less than 50 degrees, the spring assembly configured to apply spring force exclusively between the first position and the second position. 
     One embodiment of a person support apparatus may comprise a lower frame, an intermediate frame, at least one support configured to variably elevate the intermediate frame over the lower frame. A weigh frame may be supported by the intermediate frame. A deck section supported by the weigh frame may be configured to support a portion of a person&#39;s upper body thereon, the deck section configured to be inclined with respect to the weigh frame. A spring assembly may comprise a spring configured to apply spring force assisting motion of the deck section from a first position to a second position wherein the deck section in the first position is at greater angle on inclination with respect to the weigh frame than in the second position and angular inclination of the deck section in the second position is greater than 0 degrees and less than 50 degree, the spring assembly configured to apply spring force exclusively between the first position and the second position. 
     Another embodiment of a person support apparatus may comprise a head support deck section configured to be inclined with respect to a supporting frame. The person support apparatus may comprise means for providing a force exclusively between a first position and a second position, the force assisting motion of the head support deck section from the first position to the second position wherein the head support deck section in the first position is at greater angle of inclination with respect to the supporting frame than in the second position and angular inclination of the head support deck section in the second position is greater than 0 degrees and less than 50 degrees. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the claimed subject matter and, together with the description, serve to explain the principles of the claimed subject matter. In the drawings: 
         FIG. 1  is a perspective view of a person support apparatus, constructed according to one or more of the principles disclosed herein; 
         FIG. 2  is a perspective view of a portion of a person support apparatus showing a spring assembly to aid in articulation, the head support deck section is in the flat position, constructed according to one or more of the principles disclosed herein; 
         FIG. 3  is an exploded perspective view of the spring assembly for use with a person support apparatus, constructed according to one or more of the principles disclosed herein; 
         FIG. 4  is a close-up perspective view of a portion of a person support apparatus showing a spring assembly to aid in articulation, the head support deck section is in the flat position, constructed according to one or more of the principles disclosed herein; 
         FIG. 5  is a perspective view of a portion of a person support apparatus showing a spring assembly to aid in articulation, the head support deck section is at an inclination of 45 degrees with respect to the horizontal, constructed according to one or more of the principles disclosed herein; 
         FIG. 6  is a close-up perspective view of a portion of a person support apparatus showing a spring assembly to aid in articulation, the head support deck section is at an inclination of 45 degrees with respect to the horizontal, constructed according to one or more of the principles disclosed herein; 
         FIG. 7  is a perspective view of a portion of a person support apparatus showing a spring assembly to aid in articulation, the head support deck section is at full angular inclination with respect to the horizontal, constructed according to one or more of the principles disclosed herein; 
         FIG. 8  is a close-up perspective view of a portion of a person support apparatus showing a spring assembly to aid in articulation, the head support deck section is at full angular inclination with respect to the horizontal, constructed according to one or more of the principles disclosed herein. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     The embodiments of the claimed subject matter and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be briefly mentioned or omitted so as to not unnecessarily obscure the embodiments of the claimed subject matter described. The examples used herein are intended merely to facilitate an understanding of ways in which the claimed subject matter may be practiced and to further enable those of skill in the art to practice the embodiments of the claimed subject matter described herein. Accordingly, the examples and embodiments herein are merely illustrative and should not be construed as limiting the scope of the claimed subject matter, which is defined solely by the appended claims and applicable law. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. 
     It is understood that the subject matter claimed is not limited to the particular methodology, protocols, devices, apparatus, materials, applications, etc., described herein, as these may vary. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the claimed subject matter. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. 
     The subject matter herein is directed to a person support apparatus comprising systems and methods for providing spring assistance system for articulation of a head support section of the person support apparatus over a portion of the range of motion of the head support section. 
     As shown in  FIG. 1  a person support apparatus  10  comprises a lower frame  12  supported on wheels  14 . In this embodiment person support apparatus  10  is a bed, while in other embodiments the person support apparatus  10  may be a stretcher or any other furniture. An intermediate frame  18  is supported by and configured to variably elevate with respect to lower frame  12  by supports  16  as shown in  FIG. 1 . In this embodiment the intermediate frame  18  supports a weigh frame  36  (shown in  FIGS. 2, 4-8 ). At least one deck section  20  is supported on the weigh frame  36 . In this embodiment the deck section  20  comprises at least one head support deck section  38  (shown in  FIGS. 2, 4-8 ) configured to support the upper body of a person, a seat support deck section configured to support the seat section of a person and a foot support deck section  40  (shown in  FIGS. 2, 4-8 ) configured to support the feet of a person. In another embodiment the deck section  20  may comprise any number of sections. In yet another embodiment the intermediate frame  18  may serve the function of the deck section  20  and be comprised of multiple sections. 
     The person support apparatus  10  also comprises a head board  22  defining the head end, a foot board  24  defining the foot end and side rails  26  defining the lateral extremities of the person support apparatus  10 . A mattress  28  is configured to rest upon the deck section  20  of the person support apparatus  10  in this embodiment. In another embodiment, the mattress  28  may be configured to rest upon the intermediate frame  18 . A fluid supply  30  is configured to supply fluid into the mattress  28  through an inlet  32 . In this embodiment the fluid supply  30  is a compressor while in other embodiments the fluid supply  30  may be a blower or a pump. In the embodiment shown in  FIG. 1  the fluid supply is mounted on the lower frame  12 , while in another embodiment the fluid supply  30  is mounted on the foot board  24 . In other embodiments, the fluid supply  30  may be mounted on any other portion of the person support apparatus  10  such as the side rails  26  or the deck section  20 . In yet another embodiment the fluid supply  30  may be configured to rest on the floor. In this embodiment the fluid supply  30  is dedicated to the system for supplying dedicated fluid flow in a mattress, while in another embodiment the fluid supply  30  is configured to supply fluid for other uses. 
     A user interface  34  is mounted on the side rail  26  as shown in  FIG. 1  in this embodiment while in another embodiment the user interface  34  is configured to be a hand held pendant. In yet another embodiment the user interface  34  may be at a remote location and configured to communicate with the bed controller wirelessly. The user interface  34  displays system messages and/or allows a caregiver to input control parameters. A co-ordinate system is disclosed in  FIG. 1  to assist in description of relative positions and motions. As shown, X axis is configured to pass through the middle of the width of the person support apparatus. Axis Y is orthogonal to the X axis such that the X-Y plane is substantially parallel to the weigh frame. Axis Z is orthogonal to the X-Y plane. 
     Embodiments of person support systems are found in patents U.S. Pat. No. 7,296,312, U.S. Pat. No. 6,047,424 and patent application publication US2007/0266499, all of which are incorporated by reference herein. 
       FIG. 2  shows a portion of the person support apparatus  10  showing the intermediate frame  18  supporting a weigh frame  36 . The weigh frame  36  supports deck section  20 . In  FIG. 2 , a seat support deck section has been hidden to show the spring assembly  42 . Actuator  44  is configured to change the inclination of the head support deck section  38  with respect to the weigh frame  36 . The angle of inclination of the head support deck section  38  with respect to the weigh frame  36 , and thereby with respect to the X-Y plane, is also known as the head of bed (HOB) angle. As the inclination of the head support deck section  38  with respect to the weigh frame  36  is increased, at a particular HOB angle further increase in the HOB angle causes the spring assembly  42  to compress a spring  58  (shown in  FIG. 3 ). The actuator  42  acts against the spring  58  for further increase in HOB angle. In this embodiment the particular HOB angle after which further increase in HOB angle causes the spring assembly  42  to compress a spring  58  (shown in  FIG. 3 ) is 45 degrees. In another embodiment the particular HOB angle after which further increase in HOB angle causes the spring assembly  42  to compress a spring  58  is selected from a range of greater than 0 degrees and less than 50 degrees. This can be accomplished by designing and/or mounting the spring assembly to determine this angle, in one embodiment the HOB angle is determined by choosing the free length of spring  58  versus the length of the tube  48  and/or length of the rod  52  (shown in  FIG. 3 ) of the spring assembly  42 . 
       FIG. 3  is an exploded view showing one embodiment of a spring assembly  42 . Rod  52  is configured to coaxially translate within the tube  48 . The rod  52  comprises a rod pivot end  50  and a rod fastener end  54 . In this embodiment, rod  52  is mechanically connected to the head deck support section  38  by a pin joint defined by rod pivot axis A-A. A spring guide  56  is configured to slide over rod  52  and spring  58  is positioned after the spring guide  56 . Another spring guide  56  is configured to slide onto the rod after the spring  58  has been installed. In this embodiment the spring  58  comprises two physically separate sections placed in series. In another embodiment, the spring  58  comprises one section while in another embodiment the spring  58  comprises any number of sections in series and/or parallel. A washer  60  is configured to mount on the rod fastener end  54 . In this embodiment the rod fastener end  54  is threaded and a nut  62  is configured to capture the spring  58  and spring guides  56  on to the rod  52  between the rod pivot end  50  and the rod fastener end  54 . In other embodiments, any other type of fasteners may be used instead of nut  62  including but not limited to a spring loaded clamp, retaining ring and a cotter pin. The tube  48  is pivotally connected to the weigh frame  36  about the tube pivot axis B-B. In this embodiment, one end of the spring assembly  42  is connected to the head support deck section  38  at axis A-A while the other end of the spring assembly  42  is connected to the weigh frame  36  at axis B-B. In this embodiment the free length of spring  58  is less than the distance between tube pivot axis B-B and the retaining ring  46 . In this embodiment the retaining ring  46  is mounted internally in the tube  48  to limit axial motion of the spring guide  56  and spring  58  within the tube  48 . 
       FIG. 4  shows the spring assembly  42  connected to the head support deck section  38  at the rod pivot end  50  about the rod pivot axis A-A and to the weigh frame  36  about the tube pivot axis B-B. As shown in  FIG. 4 , when the head support deck section  38  is substantially parallel to the X-Y plane, the spring  58  is in an uncompressed state. 
       FIG. 5  shows the head support deck section  38  inclined at 45 degrees with respect to the X-Y plane. In this embodiment, any further increase in inclination of the head support deck section  38  results in compression of spring  58 . Therefore, any further increase in inclination of the head support deck section  38  entails overcoming the spring force required to compress spring  58  as shown in  FIG. 6 . 
       FIGS. 7 and 8  show the head support deck section  38  at its maximum inclination with respect to the X-Y plane. In this embodiment the head support deck section  38  is configured to be at an angular inclination of substantially 65 degrees with respect to the X-Y plane, while in another embodiment the maximum inclination of the head support deck section  38  may be selected as any value less than 100 degrees. As shown in  FIGS. 7 and 8  the spring  58  is compressed to a state of maximum compression when the head support deck section  38  is at maximum inclination. In this embodiment, the free uncompressed length of the spring is 6 inches while the maximum compressed length is 3 inches therefore the total compression of the spring is 3 inches. In this embodiment the spring constant (K) is selected as 30 pound force per inch (lbf/in). Using equation 1 below the magnitude of the spring force vector acting from axis A-A to axis B-B (pulling the head support deck section to a lower inclination) can be calculated. When the spring  58  is in a state of maximum compression a force of 90 lbf acts in the direction aiding the reduction of inclination of the head support deck section  38 .
 
Spring Force ( F )=Spring Constant ( K )×Spring Compression ( X )  Eq. 1
 
     In other embodiments, any value of spring compression (compressed and/or uncompressed lengths of spring) and spring constant may be selected. The spring assembly  42  described above is configured to apply a spring force acting from axis A-A to axis B-B (pulling the head support deck section to a lower inclination) from a particular HOB angle from which further increase in the HOB angle causes the spring assembly  42  to compress a spring  58  to the maximum inclination of the head support deck section  38 . 
     The spring assembly described herein serves to aid in lowering the head support deck section  38  from any angle of inclination greater than a particular HOB angle from which further increase in the HOB angle causes the spring assembly  42  to compress a spring  58 . This may be helpful in situations wherein power failure and/or failure of the electronics on the person support apparatus  10  and/or failure of the actuator  44  coincide with the need to reduce angle of inclination of the head support deck section  38  from any angle of inclination greater than a particular HOB angle from which further increase in the HOB angle causes the spring assembly  42  to compress a spring  58 . In one embodiment, administration of CPR to a person supported by the person support apparatus  10  may require reducing the angle of inclination of the head support deck section  38  and the spring assembly  42  described herein provides an assistive spring force assisting a caregiver to lower the angle of inclination of the head support deck section  38 . In this embodiment, the spring force acts exclusively from any angle of inclination greater than a particular HOB angle from which further increase in the HOB angle causes the spring assembly  42  to compress a spring  58 . In one embodiment the normal range of inclination for the head support deck section  38  for daily activities of the person supported by the person support apparatus is between 0 and 45 degrees and the spring assembly  42  is not compressed for most of the duration of use of the person support apparatus  10 . Therefore for most of the duration of use of the person support apparatus  10 , additional spring force does not need to be overcome by the actuator  44 . Since in this embodiment the spring assembly  42  is not mounted along the longitudinal centerline of the person support apparatus  10 , compression of the spring  58  may result in side loading on the head support deck section  38 . However since for most of the duration of use of the person support apparatus  10 , additional spring force does not need to be overcome by the actuator  44 , side loading on the head support deck section  38  is avoided. In another embodiment the spring assembly  42  is configured to mount along the longitudinal centerline of the person support apparatus  10  and compression of the spring  58  is configured to not result in side loading on the head support deck section  38 . 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the subject matter (particularly in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the scope of protection sought is defined by the claims as set forth hereinafter together with any equivalents thereof entitled to. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illustrate the subject matter and does not pose a limitation on the scope of the subject matter unless otherwise claimed. The use of the term “based on” and other like phrases indicating a condition for bringing about a result, both in the claims and in the written description, is not intended to foreclose any other conditions that bring about that result. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention as claimed. 
     Preferred embodiments are described herein, including the best mode known to the inventor for carrying out the claimed subject matter. Of course, variations of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventor intends for the claimed subject matter to be practiced otherwise than as specifically described herein. Accordingly, this claimed subject matter includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed unless otherwise indicated herein or otherwise clearly contradicted by context. 
     The disclosures of any references and publications cited above are expressly incorporated by reference in their entireties to the same extent as if each were incorporated by reference individually.