Patent Application
20220409460
Patient support apparatuses, such as hospital beds, stretchers, cots, tables, and wheelchairs, facilitate care of patients in a health care setting. Conventional patient support apparatuses comprise a base, a support frame, and a patient support deck upon which the patient is supported. Bariatric patient support apparatuses are generally designed to support heavier weight loads than conventional patient support beds. Certain conventional bariatric patient support apparatuses may comprise load cells for measuring the weight being supported by the base. Loading and unloading of bariatric patients from these types of known bariatric patient support apparatuses can cause high contact forces between the load cell and bed frame interface resulting in deformation of the load cell interface leading to inaccurate load scale readings.
A patient support apparatus with an additional support assembly between the load cell contact point and bed frame designed to overcome one or more of the aforementioned disadvantages is desired.
The subject disclosure is directed towards a patient support apparatus comprising a patient support deck for supporting a patient and a base frame assembly configured to support the patient support deck from a ground surface. The base frame assembly defines a longitudinal axis and a transverse axis and assembly comprises a first frame assembly supporting a plurality of wheels to facilitate movement of the patient support apparatus along the ground surface, and a second frame assembly supporting one or more lift arms coupling the patient support deck to the second frame assembly. A load cell assembly is interposed between the first and second frame assemblies to sense force acting on the first frame assembly associated with weight applied to the second frame assembly. The load cell assembly comprises: a load cell element coupled to one of the first frame assembly and the second frame assembly; a first pivot mount operatively attached to the load cell element; a second pivot mount operatively attached to the other of the first frame assembly and the second frame assembly; and a swing link. The swing link is arranged for pivoting movement relative to the first pivot mount and arranged for pivoting movement relative to the second pivot mount such that the second frame assembly is movable with respect to the first frame assembly relative to a first axis arranged parallel to the longitudinal axis, and is movable with respect to the first frame assembly relative to a second axis spaced from the first axis.
The subject disclosure is also directed towards a load cell assembly for use with a patient support apparatus comprising a base frame assembly that defines a longitudinal axis and a transverse axis and comprises a first frame assembly and a second frame assembly. The load cell comprises a first frame assembly and a second frame assembly. The load cell assembly comprises a load cell element operatively attached to the second frame assembly and cell element supporting a pivot mount. The load cell assembly also comprises a swing link is coupled to the first frame assembly. The swing link includes a first shaft arranged for pivoting movement relative to the first frame assembly, a second shaft arranged for pivoting movement relative to the pivot mount, and a link coupled to the first shaft and to the second shaft. The swing link is arranged to pivot about a pivot axis defined by the first shaft to permit the second frame assembly to move relative to the first frame assembly along the longitudinal axis.
Referring to
A support structure 32 provides support for the patient. The support structure 32 illustrated in
A mattress 49 (shown in hidden lines in
A lift device 70 may be coupled to the base 34 and the deck support frame 36 to raise and lower the deck support frame 36 to minimum and maximum heights of the patient support apparatus 30, and intermediate positions therebetween. The lift device 70 comprises one or more lift arms 72 coupling the deck support frame 36 to the base 34. The lift device 70 comprises one or more lift actuators that are coupled to at least one of the base 34 and the deck support frame 36 to raise and lower the deck support frame 36 and patient support deck 38 relative to the floor surface and the base 34. The lift device 70 may be configured to operate in the same manner or a similar manner as the lift mechanisms shown in U.S. Pat. Nos. 7,398,571, 9,486,373, 9,510,981, and/or U.S. Patent Application Publication No. 2018/0028383, hereby incorporated herein by reference.
The deck support frame 36 comprises a second longitudinal axis L2 along its length from the head end to the foot end. The construction of the support structure 32 may take on any known or conventional design, and is not limited to that specifically set forth above. In addition, the mattress 49 may be omitted in certain examples, such that the patient rests directly on the patient support surface 42.
Side rails 44, 46, 48, 50 are coupled to the deck support frame 36 and thereby supported by the base 34. A first side rail 44 is positioned at a right head end of the deck support frame 36. A second side rail 46 is positioned at a right foot end of the deck support frame 36. A third side rail 48 is positioned at a left head end of the deck support frame 36. A fourth side rail 50 is positioned at a left foot end of the deck support frame 36. If the patient support apparatus 30 is a stretcher or a cot, there may be fewer side rails. The side rails 44, 46, 48, 50 are movable between a raised position in which they block ingress and egress into and out of the patient support apparatus 30, one or more intermediate positions, and a lowered position in which they are not an obstacle to such ingress and egress. In still other configurations, the patient support apparatus 30 may not comprise any side rails.
A headboard 52 and a footboard 54 are coupled to the deck support frame 36. In other examples, when the headboard 52 and footboard 54 are utilized, the headboard 52 and footboard 54 may be coupled to other locations on the patient support apparatus 30, such as the base 34. In still other examples, the patient support apparatus 30 does not comprise the headboard 52 and/or the footboard 54.
Caregiver interfaces 56, such as handles, are shown integrated into the footboard 54 and side rails 44, 46, 48, 50 to facilitate movement of the patient support apparatus 30 over floor surfaces. Additional caregiver interfaces 56 may be integrated into the headboard 52 and/or other components of the patient support apparatus 30. The caregiver interfaces 56 are graspable by the caregiver to manipulate the patient support apparatus 30 for movement.
Other forms of the caregiver interface 56 are also contemplated. The caregiver interface 56 may comprise one or more handles coupled to the deck support frame 36. The caregiver interface 56 may simply be a surface on the patient support apparatus 30 upon which the caregiver applies force to cause movement of the patient support apparatus 30 in one or more directions, also referred to as a push location. This may comprise one or more surfaces on the deck support frame 36 or base 34. This could also comprise one or more surfaces on or adjacent to the headboard 52, footboard 54, and/or side rails 44, 46, 48, 50. In other examples, the caregiver interface 56 may comprise separate handles for each hand of the caregiver. For example, the caregiver interface 56 may comprise two handles.
Wheels 58 are coupled to the base 34 to facilitate transport over the floor surfaces. The wheels 58 are arranged in each of four quadrants of the base 34 adjacent to corners of the base 34. In the example shown, the wheels 58 are caster wheels able to rotate and swivel relative to the support structure 32 during transport. Each of the wheels 58 forms part of a caster assembly 60. Each caster assembly 60 is mounted to the base 34. It should be understood that various configurations of the caster assemblies 60 are contemplated. In addition, in some examples, the wheels 58 are not caster wheels and may be non-steerable, steerable, non-powered, powered, or combinations thereof. Additional wheels are also contemplated. For example, the patient support apparatus 30 may comprise four non-powered, non-steerable wheels, along with one or more powered wheels. In some cases, the patient support apparatus 30 may not comprise any wheels.
In other examples, one or more auxiliary wheels (powered or non-powered), which are movable between stowed positions and deployed positions, may be coupled to the support structure 32. In some cases, when these auxiliary wheels are located between caster assemblies 60 and contact the floor surface in the deployed position, they cause two of the caster assemblies 60 to be lifted off the floor surface thereby shortening a wheel base of the patient support apparatus 30. A fifth wheel may also be arranged substantially in a center of the base 34.
Referring to
The second frame assembly 76 comprises a pair of inner frame support members 82 that each extend along (e.g., parallel to) the longitudinal axis L. One or more lift arms 72 are coupled to the second frame assembly 76 between the deck support frame 36 and the inner frame support members 82 for coupling the patient support deck 38 to the inner frame support members 82.
The patient support apparatus 30 comprises a load cell assembly, generally indicated at 84, configured to sense weight applied to the first frame assembly 74 by the second frame assembly 76, as described in greater detail below. That is, the load cell assembly 84 is interposed between the first and second frame assemblies 74, 76 to sense force acting on the first frame assembly 74 associated with weight applied to the second frame assembly 76. In the representative examples illustrated herein, the patient support apparatus 30 employs a total of four load cell assemblies 84 which each support the second frame assembly 76 relative to the first frame assembly 74. More specifically, one load cell assembly 84 is coupled to each end of both of the inner frame support members 82 such that load cell assemblies 84 are arranged in each of the four quadrants of the base 34. However, and as will be appreciated from the subsequent description below, other arrangements and/or quantities of load cell assemblies 84 are contemplated by the present disclosure.
In some examples, the patient support apparatus 30 may employ a scale system that comprises a computer control system coupled in communication with one or more of the load cell assemblies 84 for measuring a weight of a patient based on signals received from the load cell assemblies 84. Additionally or alternatively, the computer control system may comprise one or more microcontrollers, field programmable gate arrays, systems on a chip, discrete circuitry, and/or other suitable hardware, software, or firmware that is capable of carrying out the functions described herein. The computer control system may be carried on-board the patient support apparatus 30, or may be remotely located.
Referring to
As noted above, in the representative examples illustrated herein, the swing support assembly 86 is coupled to the first frame assembly 74, and the load cell element 88 is coupled to the second frame assembly 76. More specifically, the load cell element 88 is coupled to an inner scale tube 90 of one of the inner frame support members 82. The load cell element 88 is mounted onto the swing support assembly 86 such that the second frame assembly 76 is movable with respect to the first frame assembly 74 along a first axis 92 parallel to the longitudinal axis L (represented by arrow 94 in
Referring to
The mounting bar 102 is coupled to an upper surface of the load cell beam element 100 (e.g., via one or more fasteners; not shown in detail) and extends outwardly from the load cell beam element 100. The second frame assembly 76 comprises an inner frame support member 82 having an inner surface that defines a frame cavity 108, and the load cell assembly 84 is at least partially positioned within the frame cavity 108 and extends outwardly from the inner frame support member 82 towards the first frame assembly 74. The mounting bar 102 is also coupled to the second frame assembly 76 (e.g., to the inner scale tube 90 of the inner frame support member 82) to support the load cell beam element 100. In some examples, such as shown in
The first pivot mount 104 is coupled to an end of the load cell beam element 100 and is mounted onto the swing support assembly 86 for movement relative thereto, as described in greater detail below. The first pivot mount 104 extends outwardly from a lower surface of the load cell beam element 100. In some examples, the load cell element 88 is coupled to the inner frame support member 82 such that the first pivot mount 104 extends outwardly from the load cell beam element 100 along (e.g., parallel to) the vertical axis V. As shown in
In a typical example, the load cell assembly 84 comprises: a load cell element 88 coupled to one of the first frame assembly 74 and the second frame assembly 76; the first pivot mount 104 operatively attached to the load cell element 88; a second pivot mount 138 operatively attached to the other of the first frame assembly 74 and the second frame assembly 76; and a swing link 116. The swing link 116 is arranged for pivoting movement relative to the first pivot mount 104 and arranged for pivoting movement relative to the second pivot mount 138 such that the second frame assembly 76 is movable with respect to the first frame assembly 74 relative to the first axis 92 arranged parallel to the longitudinal axis L, and is movable with respect to the first frame assembly 74 relative to the second axis 96 spaced from the first axis 92. In one example illustrated throughout the figures, the load cell element 88 is coupled to the second frame assembly 76 and the second pivot mount 138 is coupled to the first frame assembly 74 such that the swing link 116 is pivotably mounted on the second pivot mount 138 and the first pivot mount 104 is configured to swing on the swing link 116 thereby movably coupling the first frame assembly 74 and the second frame assembly 76. Of course, in other examples not illustrated in the drawings, the load cell element 88 is coupled to the first frame assembly 74 and the second pivot mount 138 is coupled to the second frame assembly 76 such that the swing link 116 is pivotably mounted on the first pivot mount 104 and the second pivot mount 138 is configured to swing on the swing link 116 thereby movably coupling the first frame assembly 74 and the second frame assembly 76.
In some examples, such as is shown in
The swing support assembly 86 comprises a support tube 114 and the swing link 116. The support tube 114 is mounted to the first frame assembly 74. The swing link 116 is pivotably mounted to the support tube 114, and the load cell beam element 100 is pivotably mounted to the swing link 116.
That is, the load cell element 88 is operatively attached to the second frame assembly 76 and supports the first pivot mount 104 while the swing link 116 is coupled to the first frame assembly 74. In many such examples, the swing link 116 includes a first shaft 130 arranged for pivoting movement relative to the first frame assembly 74, a second shaft 124 arranged for pivoting movement relative to the first pivot mount 104, and a link 118 coupled to the first shaft 130 and to the second shaft 124, the link 118 being arranged to pivot about a pivot axis defined by the first shaft 130 to permit the second frame assembly 76 to move relative to the first frame assembly 74 in a direction following the longitudinal axis L. More specifically, the first shaft 130 is rotatably coupled with the second pivot mount 138 and said second shaft 124 is rotatably coupled with the first pivot mount 104 to facilitate said pivoting movement.
As is described in detail below, the first shaft 130 is also configured to slide along the pivot axis to allow the second frame 76 to move in a direction parallel the transverse axis T.
The swing link 116 includes the link 118 and a pivot shaft assembly 120 coupled to the link 118. In some configurations, the link 118 includes a pair of flange plates 122 that extend between an upper portion and a lower portion of the link 118. In many such configurations, a second shaft 124 is coupled between the pair of flange plates 122 and positioned near a lower portion of the swing link 116.
In one example, each flange plate 122 includes a plate opening 126 that is defined along the upper portion and is sized and shaped to receive the pivot shaft assembly 120 therethrough. In this example, the pivot shaft assembly 120 includes a pair of bushings 128 (e.g. low friction bronze bushings and the like), a first shaft 130, and a shaft clip 131 for securing the pivot shaft assembly 120 to the link 118. The first shaft 130 extends through each bushing 128, with each bushing 128 positioned within a corresponding plate opening 126 to allow the link 118 to pivot with respect to the first shaft 130 about a first pivot axis 132 defined along a centerline axis of the first shaft 130. In addition, the bushings 128 are configured slide along an outer surface of the first shaft 130 to allow the link 118 to move with respect to the first shaft 130. That is, the bushings 128 are configured to slide along the first shaft 130 to allow the swing link 116 to move back and forth along an axis defined by the first shaft 130 such that the second frame assembly 76 is movable with respect to the first frame assembly 74 in a direction parallel the transverse axis T.
The support tube 114 is coupled to one of the cross support members 80 of the first frame assembly 74, and is mounted within a window 134 extending through the cross support member 80. The support tube 114 comprises a substantially rectangular cross-sectional shape having an inner surface that defines a bracket cavity 136 extending therethrough. The support tube 114 includes a second pivot mount 138 comprising a pair of opposing u-shaped contact surfaces 139 defined along an upper surface of the support tube 114. Each u-shaped recessed portion 139 includes an open end that is sized and shaped to receive the first shaft 130 therethrough such that the first shaft 130 is positioned within opposing u-shaped contact surfaces 139 with the swing link 116 mounted to the support tube 114. As shown in
The first pivot mount 104 is mounted onto the second shaft 124 of the swing link 116 such that the second shaft 124 contacts the arcuate contact surface 110 of the first pivot mount 104. The flange plates 122 are spaced a distance apart such that a gap 140 is defined between the opposing flange plates 122 that is sized and shaped to receive the load cell beam element 100 therethrough with the first pivot mount 104 mounted to the second shaft 124. In addition, the second shaft 124 is spaced at a distance from the first shaft 130 such that the load cell beam element 100 is positioned between the first shaft 130 and the second shaft 124 with the load cell beam element 100 mounted to the second shaft 124. With the load cell beam element 100 mounted onto the second shaft 124, the arcuate contact surface 110 of the first pivot mount 104 allows the load cell beam element 100 to pivot with respect to the second shaft 124 along a second pivot axis 142 defined along a centerline axis of the second shaft 124.
As such, the first shaft 130 is supported by the second pivot mount 138 and the second shaft 124 that supports the first pivot mount 104. The swing link 116 is configured to pivot about the first pivot axis 132 defined along a centerline axis of the first shaft 130 and pivot about the second pivot axis 142 defined along a centerline axis of the second shaft 124 to allow back and forth swinging movement of the second frame assembly 76 in a direction following the longitudinal axis L.
The swing link 116, the first pivot mount 104, and a portion of the load cell beam element 100, are positioned substantially within the bracket cavity 136 of the support tube 114. As shown in
The support tube 114 may also comprise shaft openings 144 for receiving the first shaft 103 and shaft pin 146. The shaft pin 146 is sized, shaped, and orientated to limit movement of the second frame assembly 76 along the longitudinal axis L. To this end, as shown in
The present disclosure includes a swing concept using the swing link 116 with the load cell assembly 84. The load cell element 88 is suspended from the caster frame with the link 118. The link 118 is coupled to the caster frame with the first shaft 103 which allows the link 118 and the load cell element 88 to pivot about the first shaft 103. The load cell element 88 is supported on a second shaft coupled to the link 118 that allows the load cell element 88 to swing with respect to the caster frame. The scale frame sits within the caster frame and is able to freely move longitudinally towards head end and foot end and across the width of the caster frame through the windows 134 defined through the caster frame. The scale frame can move along the longitudinal axis L and the transverse axis T as well, to account for tolerance stacks during assembly. The scale frame can swing and/or slide, giving the degrees of freedom needed for scale accuracy. In other examples, the load cell assembly 84 may also allow the scale frame to rotate, swing, slide, and/or pivot about one or more of the longitudinal, vertical, and transverse axes, providing additional degrees of freedom. The load cell element 88 is supported on the inner scale tube 90 of the scale frame. The load cell element 88 is pivotally coupled to the link allowing the longitudinal frame tolerances. The first pivot mount 104 acts as a pivot supported on the second shaft 124 of the link 118, allowing the load cell element 88 to self-align on the second shaft 124 during the assembly process. This accounts for any variation and tolerances in alignments of the weldments. During assembly, relying on gravity, the load cell assembly 84 allows the scale frame to settle out into a neutral state, thereby providing good scale accuracy results. To facilitate assembly, the windows 134 are defined in the caster frame to allow the load cell element 88 to be accessed and installed easily, as the load cell element 88 can pass through the window in the caster frame for assembly purposes. The scale frame can move from the left side to the right side and from the head end to the foot end. In some examples, the longitudinal motion of the scale frame may be limited with the end of the scale frame tube contacting the inner frame wall of the caster frame to act as an ultimate limit stop to accommodate for impact and overload testing.
To accurately weigh a patient, the scale frame must be supported through load cell elements 88 to a support the caster frame. The load cell elements 88 must only carry the weight of the scale frame; they cannot be loaded by friction between the weigh frame and bed support frame in any significant way. The load cell elements 88 may be contained within the scale frame and bed support frame with allowance for misalignment and manufacturing tolerances. To achieve this lack of load inducing friction, the load cell element 88 rests on the swing link 116 that can rotate with the load cell element 88 as well as pivot with respect to the caster frame. In addition, smooth surface finishes between mating components ensure low friction and consistent load transfer to the load cell element 88. The swing link 116 utilizes bronze bushings to obtain low friction. To contain the load cell element 88 within the frame, the load cell assembly 84 may pivot to contact retaining walls and pins (e.g. support tube 114 and shaft pin 146). The scale frame has sufficient weight to overcome friction and therefore use gravity to self-center. The retaining walls and pins have been designed such that the combination of misalignment's and manufacturing tolerances will not contact the load cell elements 88 on a still bed. This eliminates the possibility of friction between the swing link 116 and the load cell elements 88 causing inaccuracy during a scale reading. The mobility of the system due to free rotation of the swing link 116 and load cell elements 88 ensures that the system will not bind due to misalignment's and manufacturing tolerances.
The present disclosure includes the swing link 116 in tension which allows the scale system to self-center. This feature moves the load cell element 88 away from any restraining wall or pin after impact, thus improving scale accuracy. The swing support assembly self-adjusts for tolerances by design and does not require resilient materials to function, thus sustaining a larger safe working load and higher accuracy.
In this way, the examples of the present disclosure afford significant opportunities in connection with patient support apparatuses 30 by, among other things, ensuring that load cell beam elements 100 can be utilized reliably, consistently, and durably. More specifically, it will be appreciated that the load cell assemblies 84 disclosed herein can be employed without utilizing overtly-expensive load cell beams, in that the components of the load cell element 88 and the swing support assembly 86 cooperate to facilitate the relative movement between the first and second frame assemblies 74, 76 which, among other things, prevents damage to the load cell beam elements 100 and ensures consistent and reliable operation of the load cell assemblies 84.
Several examples have been discussed in the foregoing description. However, the examples discussed herein are not intended to be exhaustive or limit the disclosure to any particular form. The terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teachings and the disclosure may be practiced otherwise than as specifically described.
This application claims priority to and all the benefits of U.S. Provisional Patent Application No. 62/941,095, filed on Nov. 27, 2019.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/061966 | 11/24/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62941095 | Nov 2019 | US |
