MANAGEMENT

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Serial No. 63/080,353 filed on September 18, 2020, the disclosure of which is expressly incorporated by reference herein.

TECHNICAL FIELD

[0002] The present disclosure relates to a mattress overlay used in connection with a mattress of a patient support apparatus. More specifically, the present disclosure relates to a control unit and a mattress overlay that provides lateral rotation for the patient as well as providing moisture management to reduce the moisture at the patient’ s skin.

BACKGROUND

[0003] Patients confined to a patient support apparatus, such as a hospital bed, are at higher risk of developing medical complications such as pulmonary complications or skin breakdown. Such risks are exacerbated by excessive moisture on the occupant's skin. One source of the moisture is the occupant's own perspiration. Due to the prolonged positioning of the patient on the patient support apparatus, the moisture tends to accumulate and, along with the heat of the patient’s body, create a deleterious effect on the patient’s skin. This can result in pressure ulcers, also known as bed sores, which may become infected. The lack of movement of a patient can further exacerbate this damage.

[0004] Similarly, an immobile patient tends to develop pulmonary complications due to prolonged time in a supine position on a hospital bed. The lack of movement of the patient also tends to allow fluid to build up in the patient’s lungs, increasing the potential for pneumonia.

[0005] Various approaches to addressing the complications of patient immobility have been implemented in fully functional hospital beds or similar patient support apparatuses. The fully functional devices, while providing great benefit, can be cost prohibitive and difficult to deploy in rural environments. While various efforts have been made to address this gap, there is an ongoing need to be able to deploy the most advanced technology in a cost effective manner for those areas or situations where a fully functional hospital bed may not be available or appropriate. SUMMARY

[0006] The present disclosure includes one or more of the features recited in the appended claims and/or the following features which, alone or in any combination, may comprise patentable subject matter.

[0007] According to a first aspect of the present disclosure, a patient support system comprises a patient supporting overlay. The patient supporting overlay is adapted to be positioned and secured to a mattress. The patient supporting overlay includes a rotator, an air cushion and a moisture transfer coverlet. The rotator is operable to laterally rotate a patient supported on the overlay. The air cushion is operable to support the patient with continuous low pressure and control an interface pressure applied to the patient’s skin. The moisture transfer coverlet is operable to move moisture away from a patient’s skin to thereby cool and dry the patient’s skin. The rotator is configured to be positioned above an existing mattress body, the cushion is positioned above the rotator, and the moisture transfer coverlet is positioned above the cushion.

[0008] According to a second aspect of the present disclosure, a control box for operating a patient supporting overlay comprises a controller, a user interface, an air supply, a pneumatic circuit, and a plurality of pressure sensors. The controller includes a processor and a memory device storing instructions that are accessible by the processor to control functions of the control box. The user interface is in communication with the controller. The user interface includes a touchscreen display providing graphical data readable by a user and providing dynamic inputs to be used by the user to provide control signals to the controller. The air supply includes a driver that is in communication with and operates under the control of the controller to provide a source of air to components of the patient supporting overlay. The pneumatic circuit includes valves which are in communication with the controller. The pneumatic circuit defines, under the control of the controller, the flow of air from the air supply to various component of the patient supporting overlay. The pressure sensors are in communication with the controller and provide information regarding the operation of the patient supporting overlay. The control box is operable to operate a moisture transfer coverlet, an air cushion, and a rotator capable of providing bi-lateral rotation to a patient supported on the patient supporting overlay.

[0009] Additional features, which alone or in combination with any other feature(s), such as those listed above and/or those listed in the claims, can comprise patentable subject matter and will become apparent to those skilled in the art upon consideration of the following detailed description of various embodiments exemplifying the best mode of carrying out the embodiments as presently perceived. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The detailed description particularly refers to the accompanying figures in which:

[0011] Fig. 1 is a perspective view of a portion of a hospital bed supporting a system of the present disclosure, the system including a control box supported on the hospital bed and a patient supporting overlay supported on a mattress of the hospital bed;

[0012] Fig. 2 is a diagrammatic representation of the cross-section of the patient supporting overlay positioned on a mattress;

[0013] Fig. 3 is a diagrammatic representation similar to Fig. 2, the patient supporting overlay being shown as an exploded assembly in Fig. 3 ;

[0014] Fig. 4 is a diagrammatic top view of an air cushion of the patient supporting overlay of Fig. 1 ;

[0015] Fig. 5 is a top view of the patient supporting overlay of Fig. 1, showing the shape of turn bladders presented in phantom;

[0016] Fig. 6 is a block diagram of the control system of the system of Fig. 1 ;

[0017] Fig. 7 is a flow chart of a control algorithm for the system of Fig. 1 ;

[0018] Fig. 8 is side view of the control box of the system of Fig. 1 ;

[0019] Fig. 9 is a partial isometric view of the control box of the system of Fig. 1 with a receiver enlarged to show the arrangement of the receiver; and

[0020] Fig. 10 is a diagrammatic representation of the pneumatic circuit of the system of Fig. 1 engaged with an air source and the patient supporting overlay.

DETAILED DESCRIPTION

[0021] Referring to Fig. 1, a system 10 includes a patient supporting overlay 12 supported on a mattress 14 of a, patient support apparatus illustratively embodied as a hospital bed 16. The patient supporting overlay 12 is connected to a control box 18 such that the control box 18 provides a flow of air to the patient supporting overlay 12 and controls various functions of the patient supporting overlay 12 as will be described in further detail below. The control box 18 is configured to be supported from the hospital bed 16, but the system 10 is independent from the underlying hospital bed 16. This allows the system 10 to be deployed on any patient support apparatus, including stretchers, home care beds, at home beds, or any other location where a person or patient may be supported in a supine position on an underlying structure. Using this approach, the functionality of the system 10 is not dependent on the underlying structure.

[0022] The system 10 includes functionality necessary to provide therapy and preventative support to a patient positioned on the patient supporting overlay 12. As will be discussed in further detail below, the system 10 is configured to provide a continuous low pressure (CLP) support surface that may be operated to provide continuous later rotation therapy (CLRT). In addition, the system 10 includes a moisture transfer coverlet (MTC) that is operable to move moisture, such as perspiration, away from a patient’ s skin to reduce the incidence of skin breakdown resulting in pressure ulcers on the skin, also known as bed sores.

[0023] The operation of the system 10 can best be understood by first referring to the patient supporting overlay 12. The patient supporting overlay 12 is shown diagrammatically in Fig. 2 and in a diagrammatic exploded view in Fig. 3. The patient supporting overlay 12 includes a lower cover 20 that has a lower surface 22 that overlies a typical patient supporting structure, such as a mattress 14, for example. A pair of fabric flaps 24, 26 extend from the lower cover 20 and are configured to wrap under the mattress and be trapped between the mattress and a supporting structure under the mattress, such as the deck of the hospital bed 16, for example. The weight of the mattress, the patient supporting overlay 12, and the patient on the patient supporting overlay 12 causes the flaps 24, 26 to retain the patient supporting overlay 12 with respect to the mattress, even if deck members of the hospital bed 16 are moved.

[0024] A rotator 27, comprising a pair of turning bladders 28, 30 are positioned on an upper surface 32 of the lower cover 20. The diagrammatic view shown in Fig. 2 is shown from the foot end of the patient supporting overlay 12 so that a patient, when positioned in a supine position, lies with their right side positioned on the left of the image in Fig. 2. Thus, the turn bladder 28 is referred to as a right turn bladder 28 as it positioned on the right side of the patient. Similarly, the turn bladder 30 is referred to as the left turn bladder 30. The turn bladders 28, 30 are positioned so that the respective side of the patient is lifted with respect to the lower cover 20, and, thereby, the mattress or other structure supporting the patient supporting overlay 12. The turn bladders 28 and 30 are shown diagrammatically inflated in phantom in Fig. 4 to show the general shape of the turn bladders 28 and 30 when inflated. The turn bladders 28 and 30 are shown in phantom in Fig. 5 and the turn bladders 28, 30 are mirror images with a larger section 68 positioned near the head end 66 of the patient supporting overlay 12 and a tapered section 70 positioned nearer the foot end 72 so that the patient’s lower body does not rotate as much as the patient’s upper body when the bladders 28 or 30 are inflated.

[0025] Above the turn bladders 28, 30 is positioned an air cushion 34 which provides the primary support for the patient. The air cushion 34, while a single pneumatic volume, is a complex structure provides support to the patient and is structured as a number of interconnected chambers 40 that cooperate to distribute the patient load. Constructed from an upper sheet 36 and a lower sheet 38, the two sheets are ultrasonically welded about the periphery and at several locations throughout the cushion to form the chambers 40. It should be understood that the cushion 34 has multiple locations where the upper sheet 36 and lower sheet 38 welded together. Referring to Fig. 4, a diagrammatic representation of the cushion 34 is shown. The chambers 40 are all interconnected to allow fluid to flow throughout the chambers 40 of the cushion 34. However, seams 42 are created in various locations by welding the sheets 36, 38 together. The seams 42 cooperate to reduce the supporting area of any given chamber 40 so that the air cushion 34 operates as if the chambers 40 are individual cushions. In some locations 44, the seams 42 are cut to create slits 43 to allow adjacent chambers 40 to have some freedom of movement relative to each other. This approach provides an inexpensive method of constructing the cushion 34 while creating performance that mimics a much more complex structure.

[0026] Positioned above the cushion 34 is a coverlet 50 that provides functions as a moisture transfer coverlet 50 to move moisture that develops under a patient away from the patient’s skin and out of the moisture transfer coverlet 50. The moisture transfer coverlet 50 includes five layers including an upper layer 52 and a lower layer 54 which are joined together about the periphery. The upper layer 52 has an upper surface 56 which supports a patient. In some cases, a sheet or other bed linens may be positioned above the upper surface 56. The upper layer 52 is constructed to allow moisture, specifically moisture vapor, to transfer through the upper layer 52 and into a chamber 58 of the moisture transfer coverlet 50. The lower layer 54 is secured to the upper layer 52 and they cooperate to define the chamber 58. The lower layer 54 is vapor impermeable such that any moisture that transfers into the chamber 58 is precluded from transferring through lower layer 54.

[0027] Contained within the chamber 58 is a three-dimensional spacer fabric 60 that is non-crushable and permits air to flow through fibers of the spacer fabric 60 while still supporting the patient load. Additionally, the spacer fabric is enclosed in a nonwoven fabric having an upper layer 62 and a lower layer 64 secured together about their periphery. The nonwoven fabric allows air and vapor moisture to flow freely, while still providing an enclosure for the spacer fabric 60. [0028] In use, a flow of air is introduced into the chamber 58 near the foot end of the moisture transfer coverlet 50 and flows longitudinally from the foot end of the moisture transfer coverlet 50 to the head end of the moisture transfer coverlet 50 where it is vented out of the moisture transfer coverlet 50. Thus, the moisture that is transferred from the patient’s skin into the chamber 58 is then propelled out of the moisture transfer coverlet 50 at an opening 74 shown diagrammatically in Fig. 5.

[0029] Referring now to Fig. 6, a block diagram of the control system 100 for the system 10 is shown to include a controller 102, an air supply 103, a pneumatic circuit 104, a user interface 106, and a plurality of sensors 108. The control system 100 also includes a power supply 110 and a data port 112, illustratively embodied as a USB data port. The controller 102 includes a microprocessor 114 and a memory device 116, the memory device including instructions that, when executed by the microprocessor 114, control the operation of the control system components. Similarly, the user interface 106 also includes a microprocessor 118 and a memory device 120, the memory device 120 including instructions that, when executed by the microprocessor 118 control the operation of the user interface 106 and communication between the user interface 106 and the controller 102.

[0030] Referring to Fig. 10, the air supply 103 is illustratively embodied as a blower and has an inlet 130 and an outlet 132. In this case, the inlet 130 is connected to a filter 134 and refers to the side of the blower 103 that develops a vacuum as the blower 103 pulls air into the blower 103 while the outlet 132 is the side of the blower 103 where air is pushed out of the blower 103 to provide a positive pressure.

[0031] The pneumatic circuit 104 includes four valves 140, 142, 144, and 146, each associated with a particular function of the patient supporting overlay 12. The valve 140 is a two- way valve and is connected to a manifold 148 which is connected to the blower outlet 132 so that pressurized air in the manifold 148 may be permitted to be directed to the air cushion 34 when the blower 103 is operating when the valve 140 is opened. As will be discussed in further detail below, under certain conditions, air may be permitted to vent from the air cushion 34.

[0032] The valve 142 is also a two-way valve and is connected to the manifold 148. The valve 142 is also connected to the moisture transfer coverlet 50 chamber 58 so that when pressurized air is fed to the manifold 148 and the valve 142 is opened, pressurized air from the blower 103 is fed to the moisture transfer coverlet 50 chamber 58.

[0033] The valves 144 and 146 are each three-way valves and are associated with the right turn bladder 28 and the left turn bladder 30 respectively. The valves 144 and 146 are three- way valves so as to allow the turn bladders 28 and 30 to have the air within them drawn out by the blower 103 under a vacuum. Each of the valves 144, 146 is connected to a secondary manifold 150 which is connected to the manifold 150 to allow the pressurized air in manifold 148 to pass through manifold 150 and selectively conducted to a respective one of the turn bladders 28 or 30. The manifold 150 includes a non-powered check valve 151 that prevents back flow from the turn bladders 28 and 30 to be transferred to the manifold 148. The valves 144 and 146 are moveable between three positions, including a closed position, pressurized position, and a vacuum position. In the closed position, air does not flow through the respective valve 144 or 146. When one of the valves is in the open position, pressurized air flows through manifolds 148 and 150, through the respective valve 144 or 146 and into the respective turn bladder 28 or 30. When one of the valves 144 or 146 is in the vacuum position, the respective valve 144 or 146 connects the respective bladder 28 or 30 to a manifold 152 which is connected to the blower inlet 130 so that the blower 103 draws air from the respective bladder 28 or 30 to rapidly deflate the bladder 28 or 30. This powered deflation of the turn bladders 28 and 30 improves the performance of the CLRT function as compared to simply allowing the air to vent from the bladder 28 or 30 to atmosphere through the moisture transfer coverlet 50.

[0034] However, venting of the cushion 34 is accomplished by pausing the blower 103 so that the manifold 148 is not pressurized and opening the valve 140 so that air may enter the manifold 148. Simultaneously, valve 142 is opened to permit the air in air cushion 34 to move through manifold 148 and valve 142 to the moisture transfer coverlet 50. This is an efficient and effective approach to arranging the pneumatic circuit 104 as the need to vent the air cushion 34 is an unusual event and this approach limits the need for additional valving to accomplish venting of the air cushion 34.

[0035] The valve 142 which is associated with the moisture transfer coverlet 50, is moved to an open position in most circumstances to allow the blower 103 to push air through the moisture transfer coverlet 50 to accomplish the moisture control necessary to protect the patient’s skin.

[0036] As shown in Fig. 5, each of the bladders 28, 30, and air cushion 34 have a respective pressure sensing tube 153, 154, or 156 which is connected to a respective pressure sensor 158, 160, or 162. The pressure sensors 158, 160, or 162 provide a signal to the controller

102 indicative of the pressure in the respective air volume 28, 30, 34 so that the controller 102 can control the operation of the blower 103 and respective valves 144, 146, or 140 to control the flow of air into and out of the bladders 28 or 30 and air cushion 34.

[0037] A separate pressure sensor 164 is connected to the manifold 148 to measure the pressure in the manifold 148. The pressure in manifold 148 can be compared to the pressure in any of the bladders 28, 30 or air cushion 34 to determine if the system 10 is operating as expected. In some embodiments, the pressure sensor 164 may be omitted and the controller 102 may only rely on the signal from the pressure sensors 158, 160, and 162. In other embodiments, the pressure sensors 158, 160, and 162 may be omitted and the pressure signal from the pressure sensor 164 may be used to evaluate the pressure in the respective bladders 28, 30 or air cushion 34. The pressure sensor 164 may also be used to determine that the flow through the moisture transfer coverlet 50 is appropriate by determining whether there is an unexpected pressure rise.

[0038] The blower 103 includes a speed controller 170 which, under the control of the controller 102 can vary the speed, and thereby, the flow of air from the blower 103 to change the operating performance of the moisture transfer coverlet 50. In some embodiments, the blower

103 may be a single speed blower and the controller 102 may simply turn the blower 103 on or off through the speed controller 170.

[0039] In some embodiments, the air cushion 34 may be separated into zones, such as a head zone, a seat zone, and a foot zone, for example. In such a situation, the operation of the valve 140 and the sensor 162 would be duplicated for each zone and the zones would be controlled similarly to the above described operation and control of pressure in the air cushion 34.

[0040] As shown in Fig. 1, the control box 18 is connected to the patient supporting overlay 12 by conduit assembly 170 which has a connector 172 that engages with a receiver 174 to provide respective flow paths from each of the valves 140, 142, 144, and 146 to the respective functions of the patient supporting overlay 12. Referring now to Fig. 6, the receiver 174 has a pre-defined arrangement to mate with the connector 172 to assure that the valves 140, 142, 144, and 146 are mated to the correct corresponding function of the patient supporting overlay 12. [0041] Referring to Figs. 8 and 9, the receiver 174 has a generally circular cavity 176 with a keyway 178 offset from the cylindrical cavity 176 to align the connector 172. Referring to both Fig. 6 and Fig. 7, it can be seen that receiver 174 includes four couplers 180, 182, 184, and 186 that extend from a recessed surface 188. Each of the couplers 180, 182, 184, and 186 is generally cylindrical, each with a respective longitudinal axis 190, 192, 194, and 196. As seen in Fig. 6, the couplers 180, 182, 184, and 186 are arranged so that a line 188 perpendicular to and extending between each of the axes 192, 196 defines a horizontal axis of a coordinate system 200 for locating the couplers 180, 182, 184, and 186. Similarly, a line 198 that is perpendicular to and extends between each of the axes 190 and 194 forms the vertical axis of the coordinate system 200. The origin 202 of the coordinate system 200 is coincident with an axis 204 of the cylindrical cavity 176. Each of the couplers 180, 182, 184, and 186 are positioned such that their axes 190, 192, 194 and 196 are positioned an equal distance from the origin 202. This provides a unique pattern for connecting the connector 172 to the control box 18 to prevent other structures that have functionality different from the patient supporting overlay 12 from being connected to the control box 18.

[0042] Referring to Fig. 6, the user interface 106 allows a user to selectively control the operation of the system 10 by interacting with a touchscreen display 208 to provide inputs to the UI, and, thereby, the controller 102 through a communication link 206. The user interface 106 includes all of the functionality necessary to interact with the user and provides appropriate instructions as messages to the controller 102. The controller 102 acts on the instructions following an algorithm 210 shown in Fig. 7. The algorithm 210 begins at step 212 when the system 10 is powered on. While system 10 includes instructions for detecting errors and confirming proper operation, once the system 10 is detected to be functional, a user is prompted to enter a patient weight following a protocol shown at step 214. Once a patient weight is entered, the algorithm proceeds to step 216 and provides CLP to the patient. The algorithm monitors for a user input at step 218 and if one is detected, the algorithm advances to step 220 where a user selects the function to be modified according to a protocol represented by step 220. Step 224 identifies the function of the system 10 to be modified based on a user input. If the user selects to engage or modify CLRT at step 224, then a protocol is initiated at step 226 so that a user may select the parameters of the CLRT routine to be used. For example, the user can choose the extent of rotation of the patient in both the left and right directions respectively, as a percentage of turn. The hold time in each of the left turn, right turn, and center position can also be set for each position respectively. In some embodiments, a user may set the number of cycles to be completed or the total time for the CLRT to be active. A user may also stop the CLRT therapy from the UI. Once initiated, the CLRT therapy is provided at step 228 and the algorithm monitors for completion of the therapy. If the therapy is complete, the system 10 returns to providing the continuous low pressure support at step 216.

[0043] Similarly, if a user selects turn assist at step 224, parameters for turn assist are set according to a protocol at step 232 and turn assist is engaged at step 234. Upon completion of the turn assist function as detected at step 236, the system 10 returns to providing the continuous low pressure support at step 216.

[0044] In some cases, the user may choose to change the pressure in air cushion 34 at step 224. In this instance, the pressure in air cushion 34 is modified according to a protocol at step 238. The user may choose to deflate cushion 34, modify the pressure at which the continuous low pressure therapy is provided, or may choose to engage maximum inflation of air cushion 34 in an emergency, for example. The updated pressure is provided according to the parameters provided by the user at step 240 and the algorithm 210 monitors for completion of the modification of the pressure at step 242. If the modification is complete, as detected at step 242, then the system 10 returns to providing the continuous low pressure support at step 216.

[0045] Although this disclosure refers to specific embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the subject matter set forth in the accompanying claims.