Person support apparatus with spring assistance for articulation

A spring assist system for use with a person support apparatus is described herein. The spring assist system comprises a spring which applies a spring force on a head support deck section to aid in motion from a first position at a higher inclination to a second position at a lower inclination with respect to a supporting frame member. The spring assist system is configured to exclusively apply spring force between the first position and the second position.

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

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'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.

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 inFIG. 1a person support apparatus10comprises a lower frame12supported on wheels14. In this embodiment person support apparatus10is a bed, while in other embodiments the person support apparatus10may be a stretcher or any other furniture. An intermediate frame18is supported by and configured to variably elevate with respect to lower frame12by supports16as shown inFIG. 1. In this embodiment the intermediate frame18supports a weigh frame36(shown inFIGS. 2, 4-8). At least one deck section20is supported on the weigh frame36. In this embodiment the deck section20comprises at least one head support deck section38(shown inFIGS. 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 section40(shown inFIGS. 2, 4-8) configured to support the feet of a person. In another embodiment the deck section20may comprise any number of sections. In yet another embodiment the intermediate frame18may serve the function of the deck section20and be comprised of multiple sections.

The person support apparatus10also comprises a head board22defining the head end, a foot board24defining the foot end and side rails26defining the lateral extremities of the person support apparatus10. A mattress28is configured to rest upon the deck section20of the person support apparatus10in this embodiment. In another embodiment, the mattress28may be configured to rest upon the intermediate frame18. A fluid supply30is configured to supply fluid into the mattress28through an inlet32. In this embodiment the fluid supply30is a compressor while in other embodiments the fluid supply30may be a blower or a pump. In the embodiment shown inFIG. 1the fluid supply is mounted on the lower frame12, while in another embodiment the fluid supply30is mounted on the foot board24. In other embodiments, the fluid supply30may be mounted on any other portion of the person support apparatus10such as the side rails26or the deck section20. In yet another embodiment the fluid supply30may be configured to rest on the floor. In this embodiment the fluid supply30is dedicated to the system for supplying dedicated fluid flow in a mattress, while in another embodiment the fluid supply30is configured to supply fluid for other uses.

A user interface34is mounted on the side rail26as shown inFIG. 1in this embodiment while in another embodiment the user interface34is configured to be a hand held pendant. In yet another embodiment the user interface34may be at a remote location and configured to communicate with the bed controller wirelessly. The user interface34displays system messages and/or allows a caregiver to input control parameters. A co-ordinate system is disclosed inFIG. 1to 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. 2shows a portion of the person support apparatus10showing the intermediate frame18supporting a weigh frame36. The weigh frame36supports deck section20. InFIG. 2, a seat support deck section has been hidden to show the spring assembly42. Actuator44is configured to change the inclination of the head support deck section38with respect to the weigh frame36. The angle of inclination of the head support deck section38with respect to the weigh frame36, 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 section38with respect to the weigh frame36is increased, at a particular HOB angle further increase in the HOB angle causes the spring assembly42to compress a spring58(shown inFIG. 3). The actuator42acts against the spring58for further increase in HOB angle. In this embodiment the particular HOB angle after which further increase in HOB angle causes the spring assembly42to compress a spring58(shown inFIG. 3) is 45 degrees. In another embodiment the particular HOB angle after which further increase in HOB angle causes the spring assembly42to compress a spring58is 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 spring58versus the length of the tube48and/or length of the rod52(shown inFIG. 3) of the spring assembly42.

FIG. 3is an exploded view showing one embodiment of a spring assembly42. Rod52is configured to coaxially translate within the tube48. The rod52comprises a rod pivot end50and a rod fastener end54. In this embodiment, rod52is mechanically connected to the head deck support section38by a pin joint defined by rod pivot axis A-A. A spring guide56is configured to slide over rod52and spring58is positioned after the spring guide56. Another spring guide56is configured to slide onto the rod after the spring58has been installed. In this embodiment the spring58comprises two physically separate sections placed in series. In another embodiment, the spring58comprises one section while in another embodiment the spring58comprises any number of sections in series and/or parallel. A washer60is configured to mount on the rod fastener end54. In this embodiment the rod fastener end54is threaded and a nut62is configured to capture the spring58and spring guides56on to the rod52between the rod pivot end50and the rod fastener end54. In other embodiments, any other type of fasteners may be used instead of nut62including but not limited to a spring loaded clamp, retaining ring and a cotter pin. The tube48is pivotally connected to the weigh frame36about the tube pivot axis B-B. In this embodiment, one end of the spring assembly42is connected to the head support deck section38at axis A-A while the other end of the spring assembly42is connected to the weigh frame36at axis B-B. In this embodiment the free length of spring58is less than the distance between tube pivot axis B-B and the retaining ring46. In this embodiment the retaining ring46is mounted internally in the tube48to limit axial motion of the spring guide56and spring58within the tube48.

FIG. 4shows the spring assembly42connected to the head support deck section38at the rod pivot end50about the rod pivot axis A-A and to the weigh frame36about the tube pivot axis B-B. As shown inFIG. 4, when the head support deck section38is substantially parallel to the X-Y plane, the spring58is in an uncompressed state.

FIG. 5shows the head support deck section38inclined at 45 degrees with respect to the X-Y plane. In this embodiment, any further increase in inclination of the head support deck section38results in compression of spring58. Therefore, any further increase in inclination of the head support deck section38entails overcoming the spring force required to compress spring58as shown inFIG. 6.

FIGS. 7 and 8show the head support deck section38at its maximum inclination with respect to the X-Y plane. In this embodiment the head support deck section38is 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 section38may be selected as any value less than 100 degrees. As shown inFIGS. 7 and 8the spring58is compressed to a state of maximum compression when the head support deck section38is 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 spring58is 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 section38.
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 assembly42described 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 assembly42to compress a spring58to the maximum inclination of the head support deck section38.

The spring assembly described herein serves to aid in lowering the head support deck section38from any angle of inclination greater than a particular HOB angle from which further increase in the HOB angle causes the spring assembly42to compress a spring58. This may be helpful in situations wherein power failure and/or failure of the electronics on the person support apparatus10and/or failure of the actuator44coincide with the need to reduce angle of inclination of the head support deck section38from any angle of inclination greater than a particular HOB angle from which further increase in the HOB angle causes the spring assembly42to compress a spring58. In one embodiment, administration of CPR to a person supported by the person support apparatus10may require reducing the angle of inclination of the head support deck section38and the spring assembly42described herein provides an assistive spring force assisting a caregiver to lower the angle of inclination of the head support deck section38. 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 assembly42to compress a spring58. In one embodiment the normal range of inclination for the head support deck section38for daily activities of the person supported by the person support apparatus is between 0 and 45 degrees and the spring assembly42is not compressed for most of the duration of use of the person support apparatus10. Therefore for most of the duration of use of the person support apparatus10, additional spring force does not need to be overcome by the actuator44. Since in this embodiment the spring assembly42is not mounted along the longitudinal centerline of the person support apparatus10, compression of the spring58may result in side loading on the head support deck section38. However since for most of the duration of use of the person support apparatus10, additional spring force does not need to be overcome by the actuator44, side loading on the head support deck section38is avoided. In another embodiment the spring assembly42is configured to mount along the longitudinal centerline of the person support apparatus10and compression of the spring58is configured to not result in side loading on the head support deck section38.

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.