Aspects of various embodiments are directed to apparatuses and methods for providing support, with shear relief.
Pressurized support structures are useful for a variety of purposes. Such structures may be used to support the weight of a person. However, for certain applications involving relatively long periods of immobility or low mobility, such pressure applied can pose challenges. For instance, patients lying on a hospital bed may develop ulcers. Further, pressurized support structures can cause discomfort, relative to movement and otherwise.
These and other matters have presented challenges to the manufacture and implementation of such devices, for a variety of applications.
Various example embodiments are directed to some or all components of an apparatus and its implementation, involving the application of pressure for treatment, therapy and/or support. Such aspects may address one or more issues such as those addressed above and/or others which may become apparent. Various embodiments thus address challenges to the treatment of patients under conditions in which the patients are immobile or move very little for a period of time.
In accordance with various embodiments, an apparatus includes first and second sets of elongated pressure cells in which cells in the first set are interleaved with cells in the second set. Each set of elongated pressure cells is operable to inflate and deflate independently of the other set. The elongated pressure cells have a length and width and provide shear relief by deflecting in a direction that is perpendicular to the length of the elongated pressure cells.
Another embodiment is directed to a method as follows. A membrane is formed with recesses for first and second set of elongated pressure cells, with alternating ones of the elongated pressure cells being interleaved. A first pressure inlet channel is coupled to the first set of elongated pressure cells, and a second pressure inlet channel is coupled to the second set of elongated pressure cells. The elongated pressure are cells sealed by coupling the membrane to an underlying sheet, therein configuring each set of the elongated pressure cells to: inflate and deflate independently of the other of the first and second sets, and while inflated, provide shear relief by deflecting in a direction that is perpendicular to the length of the elongated pressure cells.
The above discussion/summary is not intended to describe each embodiment or every implementation of the present disclosure. The figures and detailed description that follow also exemplify various embodiments.
Various example embodiments may be more completely understood in consideration of the following detailed description in connection with the accompanying drawings, in which:
While various embodiments discussed herein are amenable to modifications and alternative forms, aspects thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure including aspects defined in the claims. In addition, the term “example” as used throughout this application is only by way of illustration, and not limitation.
Aspects of the present disclosure are believed to be applicable to a variety of different types of apparatuses, systems and methods involving the application of pressure with relief in a shear direction. Various embodiments are amenable to implementation for the support of the human body, such as between a support (e.g., part of a bed or chair/seat) and a person's skin or clothing. Certain embodiments are directed to ulcer prevention in a medical setting, as may be applicable to a gurney or bed, such as in a surgical setting. Other embodiments are directed to application with instances where a patient or individual is immobile for long periods of time, such as those in which the patient or individual is at risk of developing decubitus ulcers or otherwise subjected to discomfort. These and other embodiments may be implemented with a pressurized support structure that operates by applying support that alternates between different components within the structure, such as by inflating and deflating adjacent pressure cells. The pressurized support structure also provides for movement/flexibility along one or more shear directions.
In various embodiments, movement/flexibility in a shear direction is provided to allow movement of an individual along a shear direction while mitigating discomfort that may otherwise arise from surfaces that are not flexible in such a shear direction. In connection with such embodiments, it has been discovered that relative of adjacent elongated pressure cells having a length that is perpendicular to a direction of patient movement and a width that is relatively shorter than the length facilitates movement of the pressure cells along a shear direction. This movement can provide relief of shear pressure that may otherwise exist in support structures, such as by providing long cells (e.g., having a cell length that is ten or more times cell width) normal to expected movement of a body lying on the cells. Such elongated pressure cells can “roll” relative to the length dimension of the patient, which can mitigate shearing effects upon a patient's skin, which can mitigate contact pressure for reducing/minimizing stresses that cause decubitus ulcers.
It has further been discovered that such an anti-shear effect can be achieved while preventing “bottoming out” of a patent lying on the cells with some of the cells being deflated, by placing the elongated cells in relative proximity. Such support can be provided for a target weight (e.g., for a weight range of a human body lying on the cells), such that a sufficient number of elongated cells in sufficient proximity are in an inflated (and supporting) state, where the terms “sufficient” are such that the target weight is supported and being insufficient in this regard would allow bottoming out. In Further, by providing multiple small cells that interact with bony prominences of patients, movement is facilitated along with inflation/deflation of individual cells while preventing such prominences from bottoming out (e.g., through the cells to an underlying structure).
Controlling the inflation and deflation of respective pressure cells can be tailored to particular applications. For example, a first set of pressure cells that are deflated may be cycled to inflate while a second set of interleaved pressure cells remain inflated until the first set of pressure cells are partially or fully inflated, after which the second set of interleaved pressure cells are deflated. In some embodiments, a high level of support is provided during an initial period, such as when a patient is lifted onto a bed or climbs onto the bed, by inflating most or all pressure cells. After the patient has settled onto the bed and is in a relaxed position, fluid in respective sets of the cells is alternatingly with evacuated and filled to create alternating pressure support as noted herein.
In accordance with various embodiments, an apparatus includes first and second sets of elongated pressure cells in which cells in the first set are interleaved with cells in the second set. Each set of elongated pressure cells is operable to inflate and deflate independently of the other set. The elongated pressure cells have a length and width and provide shear relief by deflecting in a direction that is perpendicular to the length of the elongated pressure cells. This approach can be used to prevent flattening of the pressure cells onto the underlying surface under a patient's weight and/or prevent a portion of the patient's body from exerting direct pressure (e.g., via a collapsed pressure cell) onto an underlying surface via an empty/evacuated pressure cell.
In this context, an elongated pressure cell is a pressure cell having a length greater than its width, such that it is operable to provide shear relief in a direction along the width. This may, for example, involve a pressure cell having a length that is five, ten or more times its width. These aspects may further involve an undercut region that facilitates roll as characterized herein.
In various embodiments, each elongated pressure cell includes respective undercut regions extending along a length of the elongated pressure cell at intersections between the pressure cell and an underlying surface. For instance, where formed as part of an upper sheet that is laminated onto another sheet, the undercut may be provided at the intersection between a flat portion of that sheet and a protrusion that forms the pressure cell. The width of the elongated pressure cell at the intersection is less than a width of a cross-section of the pressure cell that is elevated above the intersection (e.g., with the pressure cell inflated), which can provide movement of the cell in response to shear pressure/movement of a patient or object in contact with an upper portion of the pressure cells. The width of such an elevated cross-section can be set sufficiently larger than the width of the elongated pressure cell at the intersection to facilitate the deflection of an upper portion of the elongated pressure cell in a direction along the width thereof, thereby providing the shear relief. In this context, a sufficiently larger width is one that permits a desired amount of deflection along the direction of the width. In some instances, the width/undercut can be set to provide movement of about 10 mm of an upper surface of the cells while imparting little or no shear force onto an object resting on the upper surface. This deflection may be exhibited, for example, when the elongated pressure cells are inflated and in contact with a patient supported thereby.
Various embodiments also include fluid delivery componentry that selectively inflates and deflates the first and second sets of elongated pressure cells. This componentry may include valving and a pump that operates to effect the inflation and deflation of the elongated pressure cells independently from one another for respective periods of time. The valving and pump may thus be implemented to inflate the first set of elongated pressure cells during a first period of time while the second set of elongated pressure cells is deflated or in a partially inflated state, and similarly inflate the second set of elongated pressure cells during a second period of time while the first set of elongated pressure cells is deflated. Evacuation and filling of the pressure cells may be carried out using fluid that is cycled between the two sets of pressure cells and/or shared in a common reservoir. For instance, a reversible pump may be used with the sets of elongated pressure cells to evacuate fluid from one of the sets of elongated pressure cells and to utilize the evacuated fluid to inflate the other one of the sets of elongated pressure cells.
Other embodiments include third and fourth sets of elongated pressure cells, with each elongated pressure cell in the third set being interleaved with elongated pressure cells of the fourth set. The elongated pressure cells in the third and fourth sets may extend in a direction that is different than the direction of the length of the elongated pressure cells in the first and second sets of elongated pressure cells.
Another embodiment is directed to a method as follows. A membrane is formed with recesses for first and second set of elongated pressure cells, with alternating ones of the elongated pressure cells being interleaved. A first pressure inlet channel is coupled to the first set of elongated pressure cells, and a second pressure inlet channel is coupled to the second set of elongated pressure cells. The elongated pressure are cells sealed (e.g., laminated) by coupling the membrane to an underlying sheet, therein configuring each set of the elongated pressure cells to: inflate and deflate independently of the other of the first and second sets, and while inflated, provide shear relief by deflecting in a direction that is perpendicular to the length of the elongated pressure cells. The size of the recesses can be set such that, when coupled to the underlying sheet, sufficient support is provided for a patient having a target weight and to prevent flattening of the pressure cells onto an underlying surface while supporting the patient.
In some implementations, each elongated pressure cell is formed with respective undercut regions extending along a length of the pressure cell at intersections between the pressure cell and an underlying surface. The width of the elongated pressure cell at the intersection is set to be less than a width of a cross-section of the elongated pressure cell that is elevated above the intersection. The elevated cross-section may, for example, have a width that is sufficiently larger than the width of the elongated pressure cell at the intersection to facilitate deflection of an upper portion of the elongated pressure cell in a direction along the width thereof (and thereby providing the shear relief).
Turning now to the Figures,
In various embodiments, the alternating pressure cells are configured and arranged to deflect under shear stress in a direction as indicated by the arrow in
A variety sizes and arrangements of pressure cells are implemented to address certain shear-stress applications. For instance, while
The construction of the apparatus 100 may also be tailored to suit particular embodiments, such as to incorporate available materials or manufacturing approaches. In some embodiments, the apparatus 100 is a two-part laminate structure with a relatively flat lower layer to which an upper layer is adhered (e.g., along edges of the apparatus at 140). The upper layer has recesses that form the pressure cells and fluid inlet channels as shown.
Each pressure cell is connected to an underlying surface at undercut regions 207, with a cross-section at the underlying surface being less than that at an elevated portion of the pressure cell (e.g., cross-section “B”). This undercut facilitates movement of an upper surface of each cell along with movement of the patient along the indicated head-to-toe direction, which runs in a direction along the width of each cell. This movement or “roll” effect helps to mitigate or prevent shear tension on the patient 202 as the patient moves relative to the table or bed (and the upper surface of the pressure cells moves with the patient with low/minimal stress). It has been discovered that this approach, together with other aspects noted herein relating to the alternation of pressure application (e.g., and related capillary blood flow enhancement) can address issues as noted herein, such as those relating to ulcers or other conditions that may develop with patients. The undercut can thus serve to relieve shear stress as the bony prominence moves in a direction tangential to the support 203, such as when a patient is positioned or repositioned, or when the support is moved (e.g., as with an adjustable bed).
In various embodiments, the size, height and spacing of the cells are set with inflation pressure therein such that a bony prominence of a patient having a target weight will not “bottom out” against the support 203, in the location of one of the deflated cells or otherwise. Accordingly, these parameters can be set relative to one another and an expected weight to be supported, relative to comfort. Further, different regions of the support pad 201 may be implemented with differently-sized pressure cells, based on expected load. For instance, a load supporting a patient's torso may be higher than a load supporting a patient's arm or leg, and regions of the support pad 201 can be tailored accordingly.
By way of example, some implementations involve cell spacing/pitch “A” of about 0.563 inches, a cell diameter “B” of about 0.5 inches (at a maximum cross-section as shown) and a cell height “C” of about 0.336 inches. A nominal inflation pressure at such sizing may be 4 psig and a nominal deflation pressure may be set equal to or less than a capillary pressure threshold for blood re-profusion, which facilitates blood flow in the patient.
In some implementations, the apparatus 200 is formed by laminating an upper membrane layer 205 with recesses for forming the pressure cells, to a lower layer 206 that seals the bottom of each pressure cell. Other embodiments involve coupling individual pressure cells to an underlying sheet. Still other embodiments involve utilizing a single material for the apparatus 200, with air injection, extrusion, molding, or other approaches.
In some embodiments, a cover or protective layer 208 is utilized to provide a positive “microclimate” (temperature and humidity) for the patient's skin. The cover 208 can be directionally compliant in the “rolling” direction of the support pad, such as along the head-to-toe direction as indicated. This may complement the shear relief aspects as noted above and achieved via the movement/roll of the respective pressure cells. The cover 208 is coupled to provide compliance in the rolling direction of the pressure cells, to mitigate the application of pressure over a deflated cell that may hinder blood flow (e.g., such that resulting contact pressure of the cover 208 against a patient's skin at locations above deflated pressure cells is below the capillary pressure threshold).
In various implementations, the support pad 201 may be implemented in accordance with the structure in apparatus 100 shown in
While the cells in
The undercut shown in
A variety of fluid delivery approaches may be implemented to suit particular embodiments.
Additional componentry may be implemented with certain embodiments, including normally closed valve 532 (e.g., with a reversible pump), check valves 534 and 536, pressure sensors 540 and 542, and a controller circuit 531. Such a controller circuit 531 may, for example, include a logic circuit that operates the pump 530 and one or more valves to alternately inflate and deflate each reservoir 510 and 520.
Terms to exemplify orientation, such as upper/lower, left/right, top/bottom and above/below, may be used herein or shown in the drawings to refer to relative positions of components, such as those shown in the figures. It should be understood that the terminology is used for notational convenience only and that in actual use the disclosed structures may be oriented different from the orientation shown in the figures. Thus, the terms should not be construed in a limiting manner.
The skilled artisan would recognize that various terminology as used in the Specification (including claims) connote a plain meaning in the art unless otherwise indicated. As examples, the specification describes and/or illustrates aspects useful for implementing the claimed disclosure by way of various circuits or circuitry which may be illustrated as or using terms such as blocks, modules, device, system, unit, controller, clamp and/or other circuit-type depictions (e.g., controller circuit 531 of
Based upon the above discussion and illustrations, those skilled in the art will readily recognize that various modifications and changes may be made to the various embodiments without strictly following the exemplary embodiments and applications illustrated and described herein. For example, methods that may be implemented in forming the apparatuses characterized herein or as otherwise noted in the Figures may involve steps carried out in various orders, with one or more aspects of the embodiments herein retained, or may involve fewer or more steps. The respective elongated portions may be implemented with different arrangements to achieve a particular effect. As another example, different types of materials and configurations can be used to facilitate anti-shear effects. Such modifications do not depart from the true spirit and scope of various aspects of the disclosure, including aspects set forth in the claims.
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