PATIENT TRANSFER DEVICE
Cross-Reference to Related Applications
[001] This application claims the benefit of priority from U.S. Provisional Application
No. 61/568,749, filed December 9, 201 1, which is incorporated herein in its entirety.
Field of the Disclosure
[002] This disclosure generally relates to patient transfer devices and, in particular,
patient transfer devices for transferring and assisting in transferring patients from one surface to
another, e.g., between beds, tables, gurneys, and/or other surfaces in a medical, hospital, and/or
other environments.
Summary of the Disclosure
[003] The disclosure relates to a patient transfer device. The transfer device may include
an inflatable mattress or air pallet having a patient support portion for receiving and/or
supporting a patient. The transfer device may also include elongated bounding portions bounding
the patient support portion at least on opposing sides. The patient support portion has an upper
side and an opposing lower side. The lower side may be curved inwardly from the bounding
portions to thereby curve upwardly away from a surface, e.g., a bed, table, gurney, or other
underlying surface on which the mattress rests when the patient support portion has no or low
loads thereon. For example, the lower side of the transfer device may be curved inwardly and
upwardly when no patient is on the patient support portion. When a patient is supported on the
support portion, the patient support portion may bow downwardly and may cause the lower side
of the patient support portion to flatten and approach the underlying surface.
[004] The transfer device may be formed of upper and lower sheets of flexible material
such as vinyl, rubber, rubberized or otherwise "sealed" fabric. Exemplary materials include, for
example, urethane-coated nylon or polyester fabric, or similar materials. It is contemplated that
the upper and lower sheets of the transfer device may alternatively be formed of a substantially
inelastic material. The upper and lower sheets may be joined at their perimeters by sewing,
thermal or ultrasonic welding, adhesives, and/or other suitable methods of attachment. It is
contemplated that the transfer device may be void of any metallic components, As it may be
radiolucent and MRI safe.
[005] The lower sheet (and thus the lower side of the patient support portion) may have
air egress apertures defined therein so that when air is supplied to the transfer device, i.e., to
inflate the mattress, a portion of the air may escape through the egress apertures and may reduce
friction between the transfer device and the underlying surface. For example, the escaping air
may form a layer of air, e.g., an air bearing, between the bottom sheet of the transfer device and
the underlying surface that, at least to some degree, cushions and/or supports the transfer device.
It is contemplated that an air layer may be formed when the transfer device is in a loaded state,
e.g., when a patient is supported by the transfer device, and in an unloaded state, e.g., when a
patient is not supported by the transfer device. In particular, an air layer may be formed when the
transfer device is in an unloaded state as the bounding portions may extend completely or
partially around the perimeter of the upwardly-curving patient support portion, may contact the
underlying support surface, and may form a seal effectively surrounding the patient support
portion. It is contemplated that gaseous fluids other than, or in addition to, air may be used to
inflate the transfer device.
[006] The bounding portions may be, when inflated, beamlike or tubelike, with a
tendency to resist bending. As such, they may form substantially, or effectively, semi-rigid
pontoon-like boundaries about the patient support portion, i.e., about the perimeter of the patient
support portion. The bounding portions, in conjunction with the downwardly-yielding patient
support portion, thereby resist a phenomenon commonly referred to as "taco-ing"- the tendency
of a transfer device to arc upward and curve about the length of a patient's body when the patient
rests upon the transfer device, with the transfer device resembling a shape approximating a "taco
shell" curving about the patient's body.
[007] The substantially concave curvature of the lower side of the patient support
portion may be formed by joining tethers, e.g., baffles as described in more detail below,
between the upper and lower sheets at their areas corresponding to the patient support portion.
The tethers may be any suitable structure configured to extend from and interconnect the lower
side to the upper side, and may include baffles, straps, or other fasteners, and may be
substantially flat or cylindrical. The tethers may delimit and establish the spacing between the
upper and lower sheets as the interior volume of the transfer device, including the volume
between the upper and lower sheets, is filled with air or other gas. The tethers located nearer to
the perimeters of the sheets may have a greater length (and thus greater spacing between the
upper and lower sheets), while the tethers located further from the perimeters of the sheets, i.e.,
closer to the middle of the patient support portion, may have shorter length (and thus lesser
spacing between the upper and lower sheets). As a result, the sheets may be held in more closely
spaced relationship further from their perimeters, and thus, further from the bounding portions,
thereby defining the concave curvature of the patient support portion.
[008] The tethers may be arranged in the form of an array of, for example, substantially
parallel, elongated, continuous strip-like baffles that extend between the opposing lateral
bounding portions of the patient support portion of the transfer device. The baffles may be
formed of the same material as the upper and lower sheets. Exemplary tethers or baffles may be
disposed between the lateral edges of the lower sheet and the lateral edges of the upper sheet. An
exemplary baffle may include a substantially linear top edge joined to the upper sheet and a
substantially concavely curving lower edge joined to the lower sheet of the mattress. The curving
lower edge may thereby define the concave curvature of the lower sheet. It is contemplated that
the curvature of the lower edge of an exemplary baffle may include any shape such that it defines
a concave-like shape as described herein, that is, a shape that may define the shape of the lower
sheet to be spaced apart from the underlying supporting surface.
[009] At different areas of the patient support portion, adjacent baffles or tethers may be
more widely spaced apart along the upper sheet than along the lower sheet. At locations along
the upper sheet where the baffles or tethers may be more widely spaced, the areas of the upper
sheet between the baffles may have a greater tendency to bulge upwardly along the upper side of
the patient support portion. This wider spacing may be provided, for example, at the area of the
patient support portion corresponding to where a patient's head would rest. As such, the resulting
upwardly-bulging area of the patient support portion may define a pillow-like raised area. In
addition or alternatively, the baffles or tethers may be relatively narrower spacing near the foot
of the patient support portion as compared to a wider spacing near the neck and/or head regions.
As such, the upper side of the patient support portion may bulge upwardly at these regions to
support the head and neck. It is contemplated that the transfer device may include safety straps
and handles along the bounding portions of the mattress.
Brief Description of the Drawings
[010] Fig. 1A is a schematic top-view illustration of a patient transfer device in
accordance with the present disclosure.
[Oi ] Fig. IB is a schematic cross-sectional illustration, taken along line A-A of the
patient transfer device of Fig. 1A, in an unloaded state.
[012] Fig. 1C is a schematic cross-sectional illustration, taken along line A-A of the
patient transfer device of Fig. 1A, in a loaded state, e.g., when supporting a patient.
[013] Fig. 2 is a schematic side-view illustration of a tether or baffle of the patient
transfer device of Fig. 1A.
[014] Fig. 3A is a schematic illustration of a first or lower sheet of the patient transfer
device of Fig. 1A.
[015] Fig. 3B is a schematic illustration of a second or upper sheet of the patient transfer
device of Fig. 1A.
[016] Fig. 4 is a schematic cross-sectional illustration, taken along line B-B of the
patient transfer device of Fig. 1A.
Detailed Description
[017] Fig. 1 illustrates a patient support device 10. The support device 10 may include a
head section 12 and a foot section 14 and may also include first and second patient bounding
portions 16, 18 disposed generally along lateral sides of the support device 10. The first and
second bounding portions or pontoons 16, 18 may extend substantially from the head section 12
to the foot section . The support device 10 may also include a patient support portion 20
generally disposed with an inner portion of the device relatively disposed between the bounding
portions 16, 18. The support device 0 may be configured as an inflatable mattress assembly or
air pallet apparatus, having an internal plenum, for supporting and transferring a patient.
[018] The support device 10 may also include one or more handles 22 and one or more
patient securing straps 24 (only partially shown for clarification purposes, and without their
associated buckles or other fasteners). It is contemplated that four handles 22 may be provided
on each lateral side of the transfer device 10, located approximately above and below the
shoulders, and above and below the hips (based on 50th percentile female shoulder breadth). It is
also contemplated that two straps 24 may be provided on each lateral side of the transfer device
10, located approximately at a thorax region and just above the knees (based on 50th percentile
male data).
[019] The transfer device 0 may also include one or more inlet ports or valves 25. The
inlet ports or valves 25 may be disposed at or adjacent to the corners of the foot of the mattress,
with each allowing attachment of a hose from a blower or pump to the mattress. The blower or
pump may supply a continuous or intermittent supply of air or other gas to the transfer device 10.
The inlet ports or valves 25 may be adapted to receive conventional hoses, e.g., hoses for pallettype
mattresses, thereby allowing use of the mattress by care providers currently using air
mattress devices.
[020] Figs. IB and C respectively illustrate the support device 10 in two states-an
unloaded state, e.g., without a patient (Fig. IB) and a loaded state, e.g., with a patient (Fig. 1C).
The bounding portions 16, 18 may have a generally rounded shape with a curved outward
surface. The bounding portions 16, 18 may also be generally void of internal structures such that
they form generally pontoon shaped tube-like or beam-like structures when the support structure
10 is inflated. The support structure 10 may also include a plurality of tethers or baffles 32
disposed laterally between the bounding portions 16, 18.
[021] As will be explained further, a downward force due to the weight of a patient 100
(Fig. 1C) may cause a downward yielding of the patient support portion 16 such that the support
device 0 has a cradling effect with respect to a patient but avoids a "taco-ing" effect. For
example, a patient may have a tendency to settle toward the center of the patient support portion
20 with the bounding portions 16, 18 situated along the patient's sides. As will be explained
below, the bounding portions 16, 8 may be relatively larger in size and extend above, below, or
both above and below the patient support portion 20. In addition, the patient support 10 may
slightly curve to form a shallow depression and cradle the patient without significantly curving
forming what is commonly referred to as "taco-ing" the patient. This cradling effect may provide
a safer and more comfortable feeling for the patient as they are transferred between different
surfaces, e.g., from a gurney to a bed, on support device 10. For example, the patient may have a
lesser risk of rolling off the support device 10 when being transferred, especially when they are
transferred between uneven surfaces but may not be "taco-ed" by the support device 10. It is
contemplated that straps 24 can also be fastened as a safety precaution to help prevent the patient
from exiting, e.g., rolling off the support device 10. It is also contemplated that because of the
cradling (and straps, if used), patients may not feel like they could roll off the support device,
and thus may tend to be calmer and more comfortable during transfers.
[022] With reference to Fig. IB, the patient support portion 20, when in an unloaded
state, may have a substantially concave shape on a first or lower side 26, relative to an
underlying surface 30, and a substantially planar or flat shape on a second or top side 28. It is
contemplated that first side 26 may have a substantially concave shape or any shape configured
to be spaced away from the surface 30 when the support device 10 is in an unloaded state. With
reference to Fig. 1C, the patient support portion 20, when in a loaded state, may have a
substantially planar shape on the first or lower side 26, relative to the surface 30, and a
substantially concave shape on the second or top side 28. The support device 10 and, in
particular, the first and second sides 26, 28, may be configured to transition and change shape
due to the weight of a patient applying a force, e.g., a downward force, relative to the surface 30.
[023] Fig. 2 illustrates an exemplary tether or baffle 32. The baffle 32 may include a
substantially concave first or bottom edge 34, a substantially linear second or top edge 36, and
lateral edges 38, 40. As such, lateral edges 38, 40 may have a relatively longer length between
first and second edges 34, 36 as compared to a middle portion of the baffle 32. It is contemplated
that the first edge 34 may have any shape such that the relative length between first and second
edges 34, 36 adjacent the lateral edges 38, 40 is greater than the middle portion of the baffle 32.
It is contemplated that the substantially concave shape of the first or lower edge 34 may be
substantially arcuate or curving, e.g., formed from a plurality of substantially straight sections
that together form a substantially curved shape, may be generally symmetric, asymmetric, or
irregular in shape, and/or may have any other suitable shape.
[024] When the transfer device 0 is inflated, the bounding portions 16, 18, which
preferably lack any internal tethers or baffles, inflate into pontoon-like forms, with the air
pressure urging the bounding portions 16, 18 into a substantially circular shape. The approximate
diameter of each circle, when measured vertically, e.g., along a direction substantially normal to
the underlying supporting surface 30, may be greater than the length of the lateral edges 38, 40
of the baffles. As such, each bounding portion or pontoon 16, 18 may be large enough to form a
barrier to reduce the likelihood that the patient will roll off the transfer device 10 while patient
supporting portion 20 may be in a substantially planar or flat configuration.
[025] The transfer device 10 may be formed from a first or bottom sheet 42 (Fig. 3A)
and a second or top sheet 44 (Fig. 3B). The first sheet 42 may have a shape as shown in Fig. 3A
substantially corresponding to the general shape of the transfer device 10, The second sheet 44
may have a substantially similar shape but different dimensions. In particular, the outer perimeter
dimensions of the first and second sheets 42, 44 may be joined together. However, a width \ of
the first sheet 42 may be greater than a width W2 of the second sheet 44. As such, a perimeter
seam between the first sheet 42 and the second sheet 44 may be located closer to the approximate
center of the second sheet 44 than the approximate center of the first sheet 42. That is, the
perimeter seam may not be aligned with the general mid-point of the bounding portions 16, 18. It
is contemplated that the lengths and/or widths of the lower and upper sheets 42, 44 may be
selected so that the bounding portions may have the desired size and/or curvature after inflation.
[026] Although of different overall shape, the first and second sheets may also be joined
to one another via the plurality of baffles 32. For example, the respective first edges 34 of baffles
32 may be joined to first sheet 42 and the respective second edges 36 of baffles 32 may be joined
to second sheet 44. It is contemplated that the respective lateral edges 38, 40 of baffles 32 may
not be joined to the first or second sheets 42, 44. As such, the relative size of the baffles 32, and
in particular the length of the lateral edges 38, 40 may define the relative spacing between the
bottom and top sides 26, 28 of the transfer device 10 and the relative size and shape of the
bounding portions 16, 18. See Figs. IB and 1C. It is also contemplated that the baffles 32 may be
respectively joined to the bottom and top sheets 42, 44 at locations illustrated in Figs. 3A and 3B,
or other according to other patterns.
[027] The first or bottom sheet 42 may include a plurality of apertures 46 formed
therein configured to permit air or other gas to escape from the interior volume of the transfer
device 10 when it is inflated. The apertures 46 may be arranged in any suitable pattern and may
be disposed in the patient support portion 20 of the transfer device 10. The apertures 46 are
generally small enough to retain a majority of the air within the transfer device 0 that may be
supplied to the interior of the transfer device 10 via one or more of the ports or valves 25 (Fig.
1A) from a supply. It is contemplated that the apertures 46 may be distributed about any area and
with any arrangement of the lower sheet as desired, but may be more densely concentrated in
areas that are likely to support a majority of a patient's weight, e.g., the patient support portion
16, whereas the bounding portions 16, 18 may be void of apertures 46.
[028] The second or top sheet 44 may be formed from a first layer configured to retain
the air within the interior of the transfer device when inflated and a second, exterior layer
permanently adhered or removably attached to an outward facing side of the first layer. The
second layer may be configured to provide comfort to the patient. It is contemplated that the
second layer may be removably affixed to the first layer such that it can be temporarily removed
from the remainder of the transfer device 10 for washing and reattached. It is contemplated that
the first and second layers of the second or top sheet 44 may have substantially the same overall
dimensions. It is further contemplated that each of the first or bottom sheet 46, the second or top
sheet 48 (including the first and second layers), and the baffles 32 may be a generally flat sheet
of material, may be substantially inelastic, and/or may be formed from any suitable material.
[029] FIG. 4 illustrates a lateral cross-sectional view of the transfer device 10 showing
an exemplary arrangement of baffles 32. As shown, the baffles 32 may be at different angles,
e.g., not parallel to one another, along all of or portions of the longitudinal length of the mattress.
As such, the baffles may affect the relative distance (or height) between the first or bottom side
and the second or top side of the patient support portion 20. For example, a large spacing and
opposing baffle angles adjacent the head end of the transfer device 10 may create a pillow for the
patient's head. Further, consistent baffle angles through a middle of the transfer device 10 may
keep the height of the transfer device 10 substantially uniform tliroughout the patient's torso. It is
contemplated that this arrangement may also help to deter "taco-ing." In the upper and lower
sheets of FIG. 2, the upper and lower sheets have different angles between each side.
[030] The size and shape of the baffles 32, in particular the substantially concave shape
of the first or bottom edge 34, and the pontoon-like bounding portions 16, 18 may promote the
tendency of the transfer device 0 to have a downwardly concave shape, at least along the lower
side of the patient support portion 16, when the transfer device is inflated and unloaded, e.g.,
without weight on it. When weight (such as a patient) is added, the downward curvature may
help keep the transfer device 0 from curving upwardly about the sides of the patient's body,
thereby reducing or eliminating "taco-ing" effects. The baffles 32 and pontoon-like bounding
portions 16, 18 may also provide a more effective "air bearing" via the apertures 46 of the first or
bottom side 26 of the transfer device 10. For example, when weight is placed on the mattress, the
substantially concave lower surface may generally flatten out, distributing a relatively thin film
of air along the lower surface between the bottom of the transfer device 10 and the underlying
surface 30 as air escapes the apertures 46. This thin film may reduce the friction between the
transfer device 10 and the surface 30 and may allow for easier transfer and movement of a
patient. Additionally, the pontoon-like bounding portions, which may have an approximate
diameter larger than the length of the baffles 32, may form a seal with the surface 30 that may
help to keep the air emitted from the lower side of the patient support portion, via the apertures
46,"trapped" under the patient support portion 20, and may allow for a more effective air
bearing. In contrast, the bottom side of patient mattresses that curve significantly, "taco-ing" a
patient, have the tendency to have their respective perimeters lift off the underlying surface,
releasing any air-bearing that may exist and have the tendency to have direct contact points
between the bottom of the mattress and the surface. Both of these may increase friction between
the mattress and the surface, which may increase the force required to move or transfer the
mattress and thus the patient.
[031] When the mattress has weight on it (particularly the weight of a patient' s body),
as shown in Fig. IB, the first or bottom side 26 of the patient support portion 20 may flatten.
When doing so, the bounding portions or pontoons 16, 18 rotate and allow the second or top side
28 of the patient support portion 16 to become substantially concave in shape. This movement
thereby creates a shallow cradling effect on the patient's body. This cradling may urge the
patient's body towards the center of the mattress, and may reduce the risk of the patient rolling
off during a transfer. Additionally, this movement may help create an air pocket beneath the
transfer device between the bounding portions and help retain air beneath the transfer device. It
is contemplated that retaining air beneath the transfer device, as compared to the rapid escape of
air, may also help reduce the effects of "taco-ing". In addition, due to the limited contact area
between the transfer device and the underlying surface, the mattress may have limited friction
when slid along the surface. In addition, friction may be further reduced by the aforementioned
air bearing. It is further contemplated that friction may be further reduced by coating the
bounding portions with a low-friction material.
[032] The drawings and description are generally directed to an exemplary embodiment
and it is contemplated that additions and modifications can be made without departing from the
scope of the invention. As an example, the configuration of the depicted transfer device can be
altered to provide mattresses of different shapes and sizes; the pontoon-like bounding portions
can be provided on opposing sides of the patient support section, on all sides, and/or might
separate adjacent patient support sections. The baffles may alternatively be formed of loops, e.g.,
substantially cylindrical baffles, of material rather than substantially planar strips. As such, the
interiors of the loops may define passages extending from the first or bottom side of the patient
support portion to the second or top side. In such embodiments, the lateral lengths of the baffles,
e.g., the length from one bounding portion to the other bounding portion, may be interrupted.
That is, a plurality of looped-shaped or cylindrical baffles may extend laterally across the width
of the patient support portion. In addition, some or all of the bounding portions might be omitted,
and possibly replaced with a descending skirt bounding the patient support portion. Rigidifying
elements (e.g., poles) might be added to the mattress where rigidity is desired, e.g., about the
opposing lateral sides of the patient support portion if the inflatable bounding portions are
removed or omitted. It is contemplated that the first sheet, the second sheet, the third sheet,
and/or the baffles or tethers may be joined to one another via any conventional technique
including, for example, welding, an adhesive, a combination of such techniques, and/or other
sealing methods,
[033] It should be understood that the foregoing description and associated drawings are
exemplary only and should not be construed as describing the only embodiments of the
invention. The true scope of the invention is to be defined by the claims.
What is Claimed
1. A patient support device, comprising:
a first side for contacting a surface, including a perimeter portion and an inner portion;
a second side for contacting a patient, including a perimeter portion and an inner portion;
at least one baffle interconnected between the first and second sides;
an unloaded state including the perimeter portion of the first side being in contact with
the surface, and the inner portion of the first side being spaced a first distance away from the
surface; and
a loaded state including the perimeter portion of the first side being in contact with the
surface, and the inner portion of the first side being spaced a second distance away from the
surface, the second distance being less than the first distance.
2. The device of claim 1, wherein the at least one baffle includes:
a first edge adjacent the first side;
a second edge adjacent the second side; and
first and second lateral edges;
wherein the first edge has a substantially concave shape with respect to the surface
between the first and second lateral edges.
3. The device of claim 2, wherein the at least one baffle is a plurality of baffles.
4. The device of claim 3, wherein the plurality of baffles includes baffles interconnected
between the first side and the second side at different angles with respect to the first side.
5. The device of claim 1, wherein:
the unloaded state further includes the inner portion of the second side spaced a third
distance away from the surface; and
the loaded state further includes the inner portion of the second side spaced a fourth
distance away from the surface, the fourth distance is less than the third distance.
6. The device of claim 1, wherein device is inflatable and the first side includes a
plurality of apertures formed therein.
7. The device of claim 1, further including:
a first pontoon portion forming a part of the perimeter portion of the first side and
forming a part of the perimeter portion of the second side; and
a second pontoon portion forming a part of the perimeter portion of the first side and
forming a part of the perimeter portion of the second side.
8. The device of claim 7, wherein the first and second pontoon portions are substantially
round having respective widths that are greater than a distance between the first side and the
second side when in the unloaded and loaded states.
9. The device of claim 1, wherein:
the first side includes a first sheet having a perimeter edge and a first lateral width;
the second side includes a second sheet having a perimeter edge and a second lateral
width, the second lateral width being less than the first lateral width; and
the a perimeter of the first sheet is joined to the perimeter of the second sheet.
10. An inflatable patient transfer mattress, comprising:
a patient support portion including a first side adjacent a patient and a second side
adjacent a supporting surface;
a first pontoon disposed on a first lateral side of the patient supporting portion;
a second pontoon disposed on a second lateral side of the patient supporting portion;
a plurality of tethers disposed laterally between the first and second pontoons and
between the first side and the second side of the patient support portion;
an unloaded state including the first and second pontoons being in contact with the
surface, and the first side of the patient support portion being spaced a first distance away from
the surface; and
a loaded state including the first and second pontoons being in contact with the surface,
and the first side of the patient support portion being spaced a second distance away from the
surface, the second distance being smaller than the first distance.
11. The mattress of claim 10, wherein:
the unloaded state further includes the second side of the patient support portion being
spaced a third distance away from the surface; and
the loaded state further includes the second side being spaced of the patient support
portion spaced a fourth distance away from the surface, the fourth distance being smaller than the
third distance.
12. The mattress of claim 11, wherein the mattress transitions from the unloaded state to
the loaded state when a patient contacts the first side.
13. The mattress of claim 10, wherein the plurality of tethers includes at least one baffle
including:
a first edge adjacent the first side;
a second edge adjacent the second side; and
first and second lateral edges;
wherein the first edge has a substantially concave shape with respect to the surface
between the first and second lateral edges.
1 . The mattress of claim 10, wherein the first side includes a plurality of apertures
formed therein configured to permit gas to escape from within an interior of the mattress and
form a gas bearing between the first side and the surface.
5. The mattress of claim 14, wherein the gas bearing is substantially enclosed by the
first and second pontoons when the mattress is in the unloaded and loaded states.
16. The mattress of claim 1 , wherein the gas is air.
17. The mattress of claim 10, wherein the plurality of tethers includes a plurality of
baffles, at least two of the plurality of baffles interconnected between the first and second sides
at different angles with respect to the first side.
18. The mattress of claim 10, wherein:
the first side includes a first sheet having a perimeter edge and a first lateral width;
the second side includes a second sheet having a perimeter edge and a second lateral
width, the second lateral width being less than the first lateral width; and
the a perimeter of the first sheet is joined to the perimeter of the second sheet.
19. The mattress of claim 10, wherein the pontoons are void of tethers.
20. A patient support mattress, comprising:
a first sheet having a first perimeter and a first width;
a second sheet having a second perimeter and a second width, the second width being
smaller than the first width;
the first perimeter joined to the second perimeter forming a first pontoon, forming a
second pontoon, forming a patient support portion, and defining an internal plenum; and
a plurality of baffles, each having a first substantially concave edge disposed adjacent and
joined to the first sheet, a second substantially linear edge disposed adjacent and joined to the
second sheet, and first and second lateral edges.