EP3210586A1

EP3210586A1 - Fluid tank receptacle for person support systems

Info

Publication number: EP3210586A1
Application number: EP17164865.2A
Authority: EP
Inventors: Richard Henry Heimbrock; Jonathan D. Turner
Original assignee: Hill Rom Services Inc
Current assignee: Hill Rom Services Inc
Priority date: 2010-07-09
Filing date: 2011-07-08
Publication date: 2017-08-30
Anticipated expiration: 2031-07-08
Also published as: WO2012006545A9; WO2012006545A2; JP2013533041A; EP3210586B1; WO2012006545A3; AU2011274503A1; EP2590610B1; EP2590610A2; JP5986077B2; JP2015211871A; EP2590610A4

Abstract

The fluid tank receptacle 38 includes a receptacle body with an opening 48 therethrough, a bumper 50, a retainer 52, and a cage 54. The opening 50 is sized to receive a fluid tank 56, such as, for example, an oxygen tank, therein. The retainer 52 is secured to the receptacle body and is configured to couple the cage 54 to the receptacle body and movably couple the bumper 50 to the receptacle body 46. The cage 54 includes a plurality of cage supports 60, a support coupler 62, and a plurality of springs 64. The spring 64 is located in the cage support slot 70 and biases the cage 54 toward the storage position. It should be appreciated that the weight of the fluid tank 56 can cause the spring 64 to compress. When the fluid tank 56 is removed, the spring 64 biases the cage 54 toward the storage position.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Applications Nos. 12/833,321 filed on July 9, 2010 , 12/836,606 filed on July 15, 2010 , 12/847,337 filed on July 30, 2010 , 61/369,499 filed on July 30, 2010 , and 61/369,152 filed on July 30, 2010 , which are hereby incorporated herein by reference in their entirety.

PART A:

BED STRUCTURE WITH A DECK SECTION MOTION CONVERTER

TECHNICAL FIELD

The subject matter described herein relates to articulable supports, such as hospital beds, and particularly to a support having a deck framework, a deck panel connected to the framework and a motion converter for coordinating a translational motion of the panel with rotation and/or longitudinal translation of the framework.

BACKGROUND

Pending US Patent application 12/618,256, filed on November 13, 2009 and entitled "Anthropometrically Governed Occupant Support" describes an articulable support, such as a hospital bed, whose articulation depends at least in part on anthropometric considerations. The contents of application 12/618,256 are incorporated herein by reference. The application discloses a mode of operation in which rotation of a bed upper body section is accompanied by longitudinal translation of the upper body section and "parallel translation" of an upper body deck panel. The application defines parallel translation as translation of the deck panel in a direction parallel to the existing angular orientation of the upper body section.
The teachings of the earlier application are presented in the context of a bed having three actuators for controlling motions of the upper body section. One of these actuators controls the parallel translation. The other two are operated to rotate the upper body section while concurrently translating it longitudinally, to rotate the upper body section without imparting any longitudinal translation, or to translate the upper body section longitudinally without imparting any rotation. Although such a system may be desirable in a prototype or experimental bed to allow maximum flexibility of articulation during testing and development, it is envisioned that beds produced for commercial sale will include fewer actuators for the upper body section. Accordingly, the application also describes a bed with a simplified kinematic configuration having a single upper body section actuator and a dual rack and pinion. In operation the actuator extends or retracts to translate the upper body section longitudinally while changing its angular orientation. At the same time the dual rack and pinion effects the desired parallel translation of the upper body deck panel in response to the translation and orientation of the upper body section.
Notwithstanding the merits of the simplified kinematics and dual rack and pinion described in the earlier application, applicants continue to pursue additional innovations which may lead to improved performance, increased reliability and reduced cost.

SUMMARY

A bed structure includes a frame, a deck framework moveably connected to the frame, a panel moveably connected to the deck framework, and a motion converter. The motion converter translates the panel relative to the deck framework in response to either or both of a) relative translation between the deck framework and the frame, and b) relative rotation of the deck framework and the frame. In one detailed embodiment the motion converter includes a rack secured to the frame, a primary gear meshing with the rack, a panel drive sprocket rotatably mounted on the deck framework coaxially with the primary gear, an idler sprocket rotatably mounted on the deck framework remote from the panel drive sprocket, a slider connected to the panel, and a chain engaged with the panel drive sprocket and the idler and connected to the slider.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the occupant support described herein will become more apparent from the following detailed description and the accompanying drawings in which:

FIG. 1A is a schematic, side elevation view of a bed of the type used in hospitals and other health care facilities.
FIG. 2A is a perspective views of a bed structure as described herein with a frame and an upper body deck section, the deck section being shown at a horizontal angular orientation relative to the frame.
FIG. 3A is a view similar to that of FIG. 2A but with the deck section at an angular orientation of about 65 degrees relative to the frame.
FIG. 4A is a closer view of a portion of FIG. 3A showing, among other things, a gear rack, a split gear housing positioned at one end of the gear rack, and the lower extremity of the deck section and also having part of a deck section rail broken away to reveal a chain and a chain housing inside the rail.
FIG. 5A is a view of the gear rack seen in FIG. 4A but with a slide rail component of the gear rack broken away, with the gear housing at the other end of the gear rack and with certain elements, such as the deck section and one side of the split gear housing, removed.
FIG. 6A is a cross sectional view taken in direction 6--6 of FIG. 2A.
FIGS. 7A and 8A are exploded views showing components of the bed structure.
FIG. 9A-10A are perspective views with selected components removed or broken away to reveal components such as a sprocket, the drive chain and a slider.
FIG. 11A is a cross sectional view taken in direction 11--11 of FIG. 10A showing the slider of FIGS 9A-10A in relation to a rail portion of the upper body deck section, a chain housing and a deck panel drive lug.
FIG. 12A is a perspective view showing a second slider in relation to the rail portion of the upper body deck section and a deck panel drive lug.
FIG. 13A is a side elavation view of a lift chain.
FIG. 14A is a schematic, side elevation view of a bed structure having a nontranslatable joint between a compression link and an elevatable frame of the bed.
FIG. 15AA - 15AD are views similar to that of FIG. 14A showing the results of various modes of motion in an embodiment in which the joint between the compression link and the elevatable frame is longitudinally translatable.

DETAILED DESCRIPTION

FIGS. 1A-3A show a hospital bed 10 extending longitudinally from a head end 12 to a foot end 14 and laterally from a left side 16 to a right side 18. FIGS. 1A-2A also show a longitudinally extending centerline 22. The bed structure includes a base frame 26 and an elevatable frame 28 connected to the base frame by folding links 30. The bed also includes four deck sections: upper body section 34, seat section 36, thigh section 38 and calf section 40, all connected to the elevatable frame. The upper body deck section 34 includes a framework 50 comprising left and right hollow rails 52, 54 joined to each other by an upper beam 56 and a lower beam 58. First and second rail slots 60, 62 penetrate through and extend part way along the top of each rail. The lower end of each rail also includes a two sided mounting bracket 64. The framework 50 is moveably connected to elevatable frame 28 so that the framework is longitudinally translatable relative to the elevatable frame and is also rotatable about pivot axis 70. Deck section 34 also includes a deck panel 72 (shown in phantom) moveably connected to the framework 50. In particular, panel 72 is translatable relative to the framework in directions P1, P2 parallel to the angular orientation α of the framework. This translation is the parallel translation referred to in the application summarized in the "Background" section of this application.
The bed also includes a pair of compression links 74 each having a frame end 76 pivotably connected to the elevatable frame at a frame joint 78 and a deck end 82 pivotably connected to the deck framework at a deck joint 84. In the embodiment illustrated in FIGS. 1A-3A frame joint 78 is not translatable relative to the frame, however in an alternate embodiment (FIG. 15A) joint 78 is longitudinally translatable relative to the frame.
The bed also includes a drive system which includes an actuator 90 having a deck end 92 connected to upper body deck framework 50 and a grounded end 94 connected to a suitable mechanical ground, such as elevatable frame 28. The drive system also includes a motion converter, indicated generally by reference numeral 100, for translating panel 72 relative to the deck framework in response to at least one of: a) relative translation between the deck framework and the frame, and b) relative rotation of the deck framework and the frame about axis 70. The illustrated embodiment includes both left and right motion converter units 100L, 100R. The units are mirror images of each other, hence it will suffice to describe only one of the units in more depth.
FIGS. 4A-8A show components and construction of one of the motion converter units in more detail. The motion converter includes a gear rack 102 affixed to elevatable frame 28. Alternatively, the gear rack may be considered to be a part of the elevatable frame. The illustrated rack comprises a single piece slide rail 104 screwed to the frame and a rack plate 106 screwed to pedestals 108 at each end of the slide rail. A slot 110 extends along the slide rail between the pedestals. The slide rail has laterally inboard and outboard sides 112, 114 each with a shoulder 116. The rack plate includes openings 120 for receiving a gear tooth. The openings have a profile that conforms to the profile of the gear teeth.
The motion converter also includes a primary gear 124 in mesh with the rack plate. The gear has a stub shaft 126 extending laterally away from bed centerline 22. A pair of lugs 128 projects laterally from the shaft. A split gear housing 130 has a rectangularly shaped opening 132 extending through its base 134, a cavity 136 inside the base and a tail 138 projecting from the base. The tail nests snugly in slide rail slot 110, and the opening 132 embraces and fits snugly around rack plate 106. An internal plate 140 resides in the cavity. Screws 142 extend through a bearing plate 144 and a backing plate 146 and into the internal plate 140 to slidingly clamp the housing to the slide rail with the bearing plate abutting rail shoulder 116. The primary gear is rotatably mounted inside gear housing 130 by way of inboard and outboard gear bushings 154, 156 and a laterally extending pivot axle 158. The pivot axle also extends through holes 162 in the rail mounting bracket 64 to connect the primary gear to the deck framework. Bearings 164 nest in the holes 162 and circumscribe pivot axle 158.
Referring additionally to FIGS. 9A-11A, The motion converter also includes a deck panel rotary drive element such as a panel drive sprocket 170. The sprocket resides inside a chain housing 172 located adjacent to and outboard of the gear housing 130. The sprocket is rotatably mounted on pivot axle 158 by way of outboard gear bushing 156. The sprocket has a stub shaft 174 extending laterally toward bed centerline 22. Notches 176 at the inboard tip of the stub shaft mate with lugs 128 on the primary gear stub shaft to rotatably connect the sprocket to the primary gear. The sprocket and the primary gear are thus coaxial and mutually corotatable. In the illustrated embodiment the pitch diameters of the primary gear and the sprocket are 37.0 and 42.6 mm respectively. Accordingly, the primary gear and sprocket exhibit a non-unity drive ratio, specifically a drive ratio of about 1.15.
The chain housing 172 extends into the hollow interior of the framework (i.e. into rail 52). The chain housing includes an internal track or ledge 182, a shoulder 184, and an elongated slot 186 that registers with first slot 60 in the framework rail. An idler sprocket 192 is rotatably mounted inside the chain housing at its remote end 194. Because the chain housing is stationary with respect to the deck framework 50, the idler can be considered to be mounted on the framework.
A slider 200 includes a slide link 202 translatably supported on housing internal track 182, and a slide block 204 bolted to the slide link. The slide link has a ledge 206 that abuts chain housing shoulder 184 to trap the slide link in the chain housing 172. The slide block includes a head portion 208 that overlies the top of framework rail 50 on either side of first rail slot 60 and a neck portion 210 that projects through the rail slot and extends to the slide link. The slider also includes a drive lug 218 projecting from the slide block. The drive lug is connected to deck panel 72, thereby connecting the slider to the panel.
Referring to FIG. 12A, a second slider 212 comprises a second slide block 214 having a head portion 226 and a neck portion 228. The second slider also includes a retainer plate 230. Head portion 226 of slide block 214 overlies the top of framework rail 52 on either side of second rail slot 62. Neck portion 228 projects through rail slot 62 and extends to the retainer plate. The slide block and retainer plate are bolted together so that the lateral sides of the retainer plate reside under the interior of framework rail 52 on either side of second rail slot 62 and so that the slider can slide longitudinally along the length of the slot. A drive lug 218 is connected to deck panel 72, thereby connecting the slider to the panel.
A roller chain 220, loops around each sprocket 170, 192 and engages with the sprocket teeth. The ends of the chain are connected to opposite ends of the slide link 202, thereby also connecting the chain to the deck panel 72. The chain is a linear or translatable drive element insofar as the part of the chain that extends linearly between the sprockets translates in direction P1 or P2 during operation of the drive system. Other kinematically equivalent devices could be used in lieu of roller chain 220. For example, a lift chain, one example of which is seen in FIG. 13A, could serve as a translatable drive element.
By virtue of the sprockets 170, 192, chain 220 and slider 200, the primary gear is operatively connected to the deck panel 72.
In operation, actuator 90 extends and pushes framework beam 58 longitudinally toward the head end 12 of the bed. The compression link 74 rotates clockwise to change the angular orientation α of the upper body deck framework. The longitudinal translation of the framework relative to the elevatable frame causes primary gear 124 to rotate in a clockwise direction as seen in FIGS. 5A, 8A, 9A and 10A. The primary gear drives the panel drive sprocket 170 in the same rotational sense. The sprocket drives the chain which acts on slider 200 to translate deck panel 72 in direction P1 relative to deck framework 50. Retraction of the actuator reverses the above described motion to translate the deck panel in direction P2.
During operation, the kinematic interaction between the gear rack 102 and the primary gear 124 serves as a means for converting the relative translation and/or rotation between the deck framework and the elevatable frame to a rotary motion of primary gear 124. The kinematic interaction between sprocket 170 and chain 220 serves as a means for converting the rotary motion to a translational motion. The slider 200 and lug 218 serve as a means for conveying the translational motion of the chain to the panel.
FIG. 14A is a simple schematic view showing the kinematic relationship of the actuator 90, elevatable frame 28, deck framework 50 and compression link 74 of the above described bed structure. Joint 78, as previously noted, is non-translatable relative to frame 28. As indicated in FIG. 14A, operation of actuator 90 causes deck panel 72 to translate longitudinally relative to the elevatable frame by a distance D and to rotate relative to the elevatable frame through an angle β. In an alternative embodiment, seen in FIG. 15A, joint 78 is longitudinally translatable relative to the frame by the action of second actuator 222. Depending on how the actions of actuators 90 and 222 are coordinated, deck framework 50 can be translated longitudinally relative to the elevatable frame 28 without any rotation of the framework (FIG. 15AB) rotated relative to the elevatable frame without any translation (FIG. 15AC) or rotated and translated as in the first embodiment (FIG. 15AD). Although the inclusion of second actuator 222 introduces additional complexity, it also introduces additional flexibility that may be desirable. Because the motion converter described herein is responsive to relative motion between the frame and the deck framework irrespective of whether that relative motion is translation, rotation, or a combination thereof, it is equally applicable to the embodiments of both FIGS. 14A and 15A.
It will be appreciated that kinematic equivalents of various components of the motion converter can be used in lieu of the illustrated components. For example belts and pulleys can be used instead of chain 220 and sprockets 170, 192; a notched or toothed belt and mating gears can also be substituted for the chain and sprockets; a roller and a track with a high coefficient of friction (to prevent roller skidding) might be substituted for the gear 124 and rack 102.

PART B

METHOD AND SYSTEM FOR CONTROLLING EVAPORATIVE AND HEAT WITHDRAWAL PERFORMANCE OF AN OCCUPANT SUPPORT SURFACE

TECHNICAL FIELD

The subject matter described herein relates to occupant support surfaces, such as hospital bed mattresses having microclimate management capabilities, and to methods and systems for controlling the evaporative performance and heat withdrawal performance of the support surface.

BACKGROUND

Hospital beds may be equipped with a support surface having microclimate management (MCM) capability. MCM capability refers to the capability to affect the environment, particularly the temperature and humidity, in the immediate vicinity of the bed occupant. The MCM-capable support surface may be a topper installed on a mattress, or may be the mattress itself. Effective microclimate management can benefit a bed occupant by resisting or mitigating the effects of skin tissue breakdown.
A typical MCM-capable support surface has provisions for receiving and discharging a stream of air. At least that portion of the support surface upon which the occupant rests is vapor permeable. In operation, a stream of air flows through the interior of the support surface. Provided the air is cooler than the occupant's skin, the internal airstream acts as a heat sink to keep the occupant's skin cool, thereby reducing the metabolic demands of the skin tissue and, as a consequence, reducing the likelihood that the occupant will develop pressure ulcers. This mode of heat transfer is proportional to the temperature gradient between the occupant's skin and the airstream (dq_DRY/dt = k₁ΔT) and is referred to herein as "dry flux", DF.
In addition, heat transfer from the occupant's skin can cause molecules of perspiration present at the interface between the support surface and the occupant's skin to acquire enough energy to break free, i.e. evaporate, from the liquid perspiration. The liberated molecules migrate through the vapor permeable portion of the occupant support, and are carried away in the internal airstream. The attendant moisture reduction at the skin/surface interface is beneficial because dry skin is less vulnerable to tissue breakdown than wet skin provided the skin is not excessively dry. Moreover, because the evaporation is the result of heat transfer from the occupant, the occupant experiences an evaporative cooling effect above and beyond the above described dry flux. This evaporative mode of heat transfer is proportional to the difference between P_H2O,SKIN, the partial pressure of water vapor (perspiration) at the occupant's skin (i.e. at the occupant/surface interface) and P_H2O,STREAM,the partial pressure of water vapor in the airstream (dq_WET/dt = k₂ΔP_H2O) and is referred to herein as "wet flux", WF. The wet flux component of heat transfer materializes only when the occupant is perspiring and depositing liquid phase perspiration at the skin/surface interface.
Typically, the air flowing through the MCM-capable surface is ambient air (e.g. air from a hospital room), unconditioned in the sense that no temperature and/or humidity conditioning has been applied to the air above and beyond the conditioning applied by the hospital heating, ventilating and air conditioning (HVAC) system. As a result, the effectiveness of the MCM-capable support surface is constrained by the properties of the room air. What is needed is a way to selectively achieve enhanced microclimate performance and to govern the degree of enhancement.

SUMMARY

A method for controlling performance of an MCM capable support surface having a flowpath for guiding a stream of air along at least a portion of the surface, comprises specifying a desired evaporative performance greater than an evaporative performance achievable with unconditioned ambient air, chilling the unconditioned ambient air to a temperature at least as low as that required to achieve 100% relative humidity, thereby demoisturizing the air, and supplying the chilled, demoisturized air to the flowpath. The method may also include the step of heating the chilled, demoisturized air prior to the step of supplying it to the flowpath.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the various embodiments of the system and method for enhancing and controlling microclimate performance of a support surface described herein will become more apparent from the following detailed description and the accompanying drawings in which:

FIG. 1B is a schematic, side elevation view of a bed having an MCM-capable support surface.
FIG. 2B is a view taken in the direction 2--2 of FIG. 1B.
FIG. 3B is a schematic of a microclimate management system including a chiller and a water collection system as disclosed herein.
FIG. 4B is a schematic of a microclimate management system similar to that of FIG. 3B but also including a heater.
FIG. 5B is a block diagram of an algorithm for controlling evaporative capacity of a support surface.
FIG. 6B is a graph showing vapor pressure of water as a function of temperature and including data symbols corresponding to numerical examples described herein.
FIG. 7B is a view taken in direction 7--7 of FIG. 2B showing a nucleation device comprising an array of vertically oriented fibers.
FIGS. 8BA and 8BB are views of a user interface showing two possible ways for permitting a caregiver to specify a desired performance of the microclimate management system.

DETAILED DESCRIPTION

Referring to FIGS. 1B-2B, a bed 20 has a support surface 22 with microclimate management (MCM) capability. The MCM-capable support surface is depicted as a topper installed on top of a non-MCM-capable mattress, but could instead be the mattress itself. The support surface supports an occupant 24. The support surface comprises a material layer 26 bounding and at least partly defining an internal fluid flowpath 30. Portion 32 of the support surface is the portion upon which the occupant rests, and is vapor permeable. The support surface includes an air intake 36 and an air exhaust vent 38. During operation a stream 40 of air flows through the flowpath to serve as a sink for heat and water vapor. The bed also includes a user interface 42 for receiving user instructions concerning the operation of a microclimate management system (FIGS. 3B, 4B). The illustrated user interface includes a keypad 44 for receiving the user's instructions and a display panel 46 for conveying information to the user. The bed also includes a controller 50, responsive to the user's instructions, for controlling the microclimate management system. Referring to FIGS. 3B-4B, the microclimate management system includes a chiller 60, a water collection system 62 and, in one embodiment, a heater 64.
Before further describing the method and system for enhanced microclimate management, it will be useful to establish certain definitions and concepts.
Two principal mechanisms of heat transfer affect the microclimate. One mechanism, dry heat transfer, is proportional to temperature difference and is independent of the presence or absence of liquid phase perspiration at the occupant/surface interface. The potential of the support surface to effect dry heat transfer at a given temperature difference is referred to as its dry flux capacity, DFC. The dry heat transfer actually realized during operation of the system described herein is the actual dry flux, DF. Because the dry heat transfer is independent of whether or not liquid phase perspiration is present at the occupant/surface interface, the actual dry flux DF equals the dry flux capacity DFC: $DF = DFC = (1 / R_{DRY}) (T_{SKIN} - T_{STREAM})$
where:

R_DRY is a property of the MCM-capable surface 22, (particularly portion 32 of the support surface) in combination with the condition (e.g. temperature and flow rate) of the air stream 40 and the proximity of the airstream to the occupant's skin. Specifically, R_DRY is a system constant that characterizes the resistance of the support surface and airstream to dry heat flow. The inverse, 1/R_DRY, has units of power per unit area per temperature degree, for example watts/meter²/°C. Low values of R_DRY correspond to high heat transfer; high values of R_DRY correspond to low heat transfer. In the examples presented below R_DRY has a value of 0.300 (m²°C)/watt.

T_SKIN is the temperature of the occupant's skin at the occupant/surface interface. T_SKIN has units of temperature such as degrees Centigrade (°C); and
T_STREAM is the temperature of the air stream 40. For purposes of the present disclosure and the accompanying numerical example, and in many practical applications, T_STREAM can be approximated as being equal to the ambient room air temperature, T_AMBIENT. Such an approximation neglects the effect of temperature changes imparted to the ambient air as it travels to and through the topper. These temperature changes may be due to a number of factors such as temperature changes associated with pressurizing the room ambient air to cause it to flow through the topper, heat transfer arising from heat rejection by nearby electronic components, and heat transferred into the airstream from the occupant. T_STREAM has units of temperature such as degrees Centigrade (°C).
Dry flux capacity DFC and dry flux DF have units of power per unit area, for example watts/meter².
The value of R_DRY for a given system can be determined experimentally by way of a "dry plate test". A dry test plate, heated to a test temperature of 36°C (a reasonable "standard" human skin temperature based on extensive measurements) is placed on a surface. A stream of air at a known temperature lower than 36°C is caused to flow along the opposite side of the surface. Energy is supplied to the plate at a rate sufficient to maintain its temperature at 36°C despite the cooling effect of the test airstream. These numerical values are used in equation (1) (36° is used as the value of T_SKIN; the temperature of the test air stream is used as the value of T_STREAM; the power per unit area of test plate supplied to keep the test plate at a constant temperature of 36° is used as the value of dry flux, DF). Equation (1) can then be solved for R_DRY.
The second mechanism of heat transfer, wet heat transfer, is proportional to the difference in the partial pressure of water vapor (perspiration) at the occupant's skin and the partial pressure of water vapor in the airstream 40. The potential of the support surface to effect wet heat transfer is its wet flux capacity, WFC. The wet heat transfer actually realized during operation of the system described herein is the actual wet flux, WF. The wet flux capacity WFC is realized as actual wet flux WF when perspiration is available for evaporation at the skin/surface interface. The rates of potential and actual wet heat transfer are referred to as wet flux capacity WFC and wet flux WF respectively, and can be expressed as: $WFC = (1 / R_{WET}) (T_{H 2 O, SKIN} - T_{H 2 O, STREAM})$
$WF = (1 / R_{WET}) (T_{H 2 O, SKIN} - T_{H 2 O, STREAM})$
where:

R_WET is a property of the MCM-capable support surface 22 (particularly portion 32 of the support surface) in combination with the condition (e.g. temperature and flow rate) of the air stream 40 and the proximity of the airstream to the occupant's skin. Specifically, R_WET is a system constant that characterizes the resistance of the support surface and airstream to evaporative cooling. Its inverse, 1/R_WET has units of power per unit area per unit pressure, for example watts/meter²/pascal. Low values of R_WET correspond to high evaporative heat transfer; high values of R_WET correspond to low evaporative heat transfer. In the examples presented below R_WET has a value of 250 (m²Pa)/watt.

P_H2O,SKIN is the partial pressure of water vapor (perspiration) at the occupant's skin (i.e. at the occupant/surface interface) P_H2O,SKIN has units of pressure such as Pascals (Pa); and
P_H2O,STREAM is the partial pressure of water vapor in the airstream 40. If T_STREAM is approximated as being equal to T_AMBIENT, P_H2O,STREAM can be approximated as being equal to the partial pressure of water vapor at room air ambient temperature. P_H2O,STREAM has units of pressure such as Pascals (Pa).
Although the right sides of equations 2A and 2B are identical in form, equation 2A applies without restriction because it describes the potential or capacity of the system. The applicability of equation 2B is restricted to those conditions when liquid perspiration is being deposited at the occupant/surface interface because it describes the actual wet heat transfer, which materializes only when liquid perspiration is being made available for evaporation.
Wet flux capacity WFC and wet flux WF have units of power per unit area, for example watts/meter².
The value of R_WET for a given system can be determined experimentally by way of a "wet plate test". First, a dry plate test is conducted as described above. The test is then repeated with a supply of water directed to the plate to ensure that the entire test plate remains wet throughout the test. Energy is supplied to the plate at a rate sufficient to maintain its temperature at 36°C despite the combined effect of dry heat transfer and evaporative cooling attributable to the test airstream. Appropriate numerical values from the test are then substituted into equation (2A or 2B). The value used for WF (or WFC) is the difference between the power supplied to the test plate during the wet phase of the test and the power supplied during the dry phase of the test. Because liquid moisture is present at the test plate / surface interface during the test, the value used for P_H2O,SKIN is 5946 Pa, which is the partial pressure of water vapor at 36°C and 100% relative humidity (i.e. the saturation pressure). P_H2O,STREAM is determined by multiplying measured relative humidity of the ambient room air by the saturation pressure of water vapor at the prevailing room temperature. Equation (2) can then be solved for R_WET.
As is evident from the foregoing, RDRY and RWET are system specific constants, i.e. they are properties of the material used to make the surface, or at least the surface portion 32 of interest, of the condition of the airstream 40 passing through the support surface and of the proximity of the airstream to the occupant's skin. The factors TSTREAM, TSKIN, P_H2O,STREAM and P_H2O,SKIN are environmental related factors because their values depend on the temperature and humidity of the room air and the conditions prevalent at the occupant's skin.
Total heat withdrawal capacity THWC is the sum of dry flux capacity DFC and wet flux capacity WFC. Actual total heat withdrawal THW is the sum of dry flux DF and wet flux WF: $THWC = DFC + WFC$
$THW = DF + WF$
For the present application, it is useful to represent wet flux capacity and wet flux, which have units of energy per unit time per unit area, as an evaporative capacity EC and an evaporative rate ER , which have units of mass (of water) per unit time per unit area. At approximately 36°C the heat of vaporization of water is about 2420 joules per gram. In other words it takes about 2420 joules (2420 watt-seconds or 0.672 watt-hours) of energy to evaporate one gram of water. Accordingly, one watt/m² of wet flux capacity corresponds to 1.489 gm/hour/m² of evaporative capacity, and one watt/m² of actual wet flux corresponds to 1.489 gm/hour/m² of actual evaporative rate: $EC = 1.489 WFC$
$ER = 1.489 WF$
where:

EC and ER are evaporative capacity and evaporative rate expressed in grams per hour per square meter, 1.489 is the inverse of the heat of vaporization of water at 36°C expressed in grams per joule, and WFC and WF are wet flux capacity and actual wet flux expressed in grams per watt-hour.

Using Equations (1), (2A) and (2B), equations (3A) and (3B) can be rewritten as: $THWC = (1 / RDR Y) (TSKIN - TSTREAM) + (1 / RWET) (PH 2 O, SKIN - PH 2 O, STREAM)$
$THW = (1 / RDRY) (TSKIN - TSTREAM) + (1 / RWET) (PH 2 O, SKIN - PH 2 O, STREAM)$
or alternatively as: $THWC = (1 / RDR Y) (TSKIN - TSTREAM) + EC / 1.489$
$THW = (1 / RDR Y) (TSKIN - TSTREAM) + EC / 1.489$
where: $EC = 1.489 WFC = (1.489 / RWET) (PH 2 O, SKIN - PH 2 O, STREAM)$
$ER = 1.489 WF = (1.489 / RWET) (PH 2 O, SKIN - PH 2 O, STREAM)$
subject to the condition that the equations representing system potential or capacity (equations 5A, 6A, 7A) apply irrespective of whether or not liquid perspiration is being deposited at the occupant/surface interface, and the equations representing actual performance (equations 5B, 6B, 7B) apply only when liquid perspiration is being deposited at the occupant/surface interface.
If the values of the system constants R_DRY and R_WET and of the environmental parameters T_SKIN, T_STREAM, P_H2O,SKIN, P_H2O,STREAM are known, equations (5A), (6A) and (7A) can be used to determine the potential total heat withdrawal THWC and the evaporative capacity EC available to cool the bed occupant. Similarly, equations (5B), (6B) and (7B) can be used to determine the actual total heat withdrawal THW and evaporation rate applied to the bed occupant provided the condition for using those equations (the presence of perspiration available for evaporation at the occupant/surface interface) is met. T_SKIN can be determined from actual skin temperature measurements or can be represented by a standard value, such as 36°C. P_H2O,SKIN can be represented as the partial pressure of water vapor at T_SKIN and at the relative humidity prevailing at the occupant/surface interface. When there is liquid phase perspiration available for evaporation at the occupant/surface interface the relative humidity will be 100%. If a standard value of 36°C is used as the value of T_SKIN, at 100% relative humidity, P_H2O,SKIN can be expressed as 5946 Pa.
Alternatively, if a desired evaporative rate ERDESIRED is specified, the parameters RWET, RDRY, TSKIN, PH20,SKIN, room ambient air temperature TAMBIENT and room relative humidity RHAMBIENT can be used to calculate stream conditions TSTREAM,REQUIRED and PH2O,STREAM,REQUIRED required to achieve the specified evaporative rate and the resulting total heat withdrawal. Equations 5, 6 and 7 are rewritten below as equations 5C, 6C and 7C to reflect that evaporative rate is the user specified parameter whereas TSTREAM, PH2O,STREAM, and THW are dependent parameters. Equations 5C through 7C assume the presence of perspiration to be evaporated at the skin / support surface interface. $\begin{array}{l} WFREQUIRED = ERDESIRED / 1.489 = \\ (1 / RWET) (PH 2 O, SKIN - PH 2 O, STREAM, REQUIRED) \end{array}$
$\begin{matrix} THW = (1 / RDRY) (TSKIN - TSTREAM, REQUIRED) + \\ (1 / RWET) (PH 2 O, SKIN - PH 2 O, STREAM, REQUIRED) \end{matrix}$
or alternatively: $THW = (1 / RDRY) (TSKIN - TSTREAM, REQUIRED) + ERDESIRED / 1.489$
As another alternative, if a desired total heat withdrawal THWDESIRED is specified and exceeds the pre-existing total heat withdrawal, the desired total heat withdrawal might be obtainable by increasing dry flux alone, or may require a combination of increased wet flux and increased dry flux, although the apportionment of dry flux and wet flux cannot be independently specified for a given THWDESIRED. Indeed, some specifications of total heat withdrawal may require more wet flux (evaporative cooling) than is desired. Equations 5, 6 and 7 are rewritten below as equations 5D, 6D and 7D to reflect that THW is the user specified parameter whereas stream conditions TSTREAM, P_H2O,STREAM and EC are dependent parameters. Equations 5D through 7D assume the presence of perspiration to be evaporated at the skin / support surface interface. ${THW}_{DESIRED} = (1 / R_{DRY}) (T_{SKIN} - T_{STREAM, REQUIRED}) + (1 / R_{WET}) (P_{H 2 O, SKIN} - P_{H 2 O, STREAM, REQUIRED})$
or alternatively: ${THW}_{DESIRED} = (1 / R_{DRY}) (T_{SKIN} - T_{STREAM, REQUIRED}) + {ER}_{REQUIRED} / 1.489$
where: ${ER}_{REQUIRED} = 1.489 {WF}_{REQUIRED} = (1.489 / R_{WET}) (P_{H 2 O, SKIN} - P_{H 2 O, STREAM, REQUIRED})$
As noted above, the determination of required stream conditions by way of equations 5C-7C and 5D-7D can be simplified somewhat by using 36°C as the value for T_SKIN, and using 5946 Pa, the vapor pressure of water at 36°C and 100% RH, as the value for P_H2O,SKIN.
Operation of the MCM-capable support surface and the microclimate management system of FIG. 3B can be understood by referring to the graph of FIG. 6B which shows pressure expressed in pascals (Pa) as a function of temperature expressed in °C. Line VP represents the vapor pressure of water, and may also be referred to as the saturation line or as a line of 100% relative humidity, RH. The circular symbol represents a perspiring bed occupant whose skin temperature T_SKIN is 36°C. Because of the perspiration at the occupant/support surface interface, the relative humidity at the interface is 100% which, at 36°C, corresponds to a vapor pressure of 5946 Pa.
The square symbol represents room ambient air, having a temperature of 25.6°C and a relative humidity of 75%, corresponding to P_H2O,AMBIENT of 2451 Pa. The room ambient air is unconditioned in the sense that no temperature or humidity conditioning has been applied to it above and beyond that applied by the facility HVAC equipment. If the airstream 40 flowing through the support surface flowpath 30 comprised this unconditioned ambient air, the occupant would experience, in accordance with equations (1) through (4) and with R_DRY= 0.300 (m²°C)/watt and R_WET = 250 (m²Pa)/watt:

ER = 20.8 gm/hr/m², corresponding to a partial pressure difference of 3495 Pa;
WF = 14.0 watt/m²;
DF = 34.7 watt/m², corresponding to a temperature difference of 10.4 °C; and
THW = 48.7 watt/m²

If it were desired to increase the evaporative cooling, a user such as a nurse or other caregiver would use keypad 44 to specify a desired evaporative rate ER of, for example, 24.0 gm/hr/m², which is greater than the 20.8 gm/hr/m² achievable with the unconditioned ambient air. In response to the user's instructions, controller 50 commands operation of chiller 60 to chill the ambient air to 16.8°C (triangular symbol), which is lower than the 20.8°C temperature required for the ambient air to be brought to a condition of 100% relative humidity (elliptical symbol). As seen on the graph, the chilling from 25.6°C to 20.8°C lowers the temperature of the air at a constant partial pressure of water vapor until relative humidity rises to 100%. This segment of the chilling process increases the dry flux capacity of the air (and also increases the actual dry flux) but, due to the absence of any change in partial pressure, does not increase its wet flux capacity or the actual wet flux. The cooling from 20.8°C to 16.8°C proceeds along saturation line VP and causes water vapor to condense, thereby demoisturizing the air (i.e. removing water molecules from the mixture of gas phase H₂O molecules and gaseous air). This segment of the chilling process has the intended effect of increasing wet flux capacity WFC and actual wet flux WF, and therefore evaporative capacity EC and evaporation rate ER (due to the reduction in partial pressure from 2451 Pa to 1916 Pa) and also further increases dry flux capacity and dry flux (due to the additional temperature reduction from 20.8°C to 16.8°C).
The water removal system 62 drains or otherwise removes the liquid water. The illustrated water removal system includes a nucleation device 66 to promote and enhance the efficiency of the transition from the gaseous phase to the liquid phase. Referring to FIG. 7B, one example nucleation device is a device having an array of vertically oriented fibers 68 projecting into airstream 40. The fibers converge into a funnel 70. Water droplets collect on the fibers. The weight of the water droplets causes them to migrate down the fibers where they drip into the funnel, which channels the water out of the system. The chilled, demoisturized air is then supplied to the support surface internal flowpath 30 where its enhanced dry flux capacity and wet flux capacity are manifested as actual heat transfer.

Table 1, below, compares the performance parameters of the microclimate management system using unconditioned ambient air (25.6°C and 75% RH) and air chilled air as described above. Note that the 31.4 gm/hr/m² increase in total heat withdrawal comprises 2.1 gm/hr/m² of wet flux and 29.3 gm/hr/m² of dry flux. Of the 29.3 gm/hr/m² of dry flux, 13.3 gm/hr/m² is dry flux resulting from the cooling required to achieve the 2.1 gm/hr/m² of wet flux.

TABLE 1

Parameter	Ambient Air	Chilled to 16.8 °C	Change
Temperature (°C)	25.6	16.8	-8.8
ER (gm/hr/m²)	20.8	24.0	3.2
WF (watt/m²)	14.0	16.1	2.1
P_H2O (Pa)	2451	1916	-535
DF (watt/m²⁾	34.7	64.0	29.3
THW (watt/m²⁾	48.7	80.1	31.4

The above described method and system may, as a consequence of increasing the evaporative rate, result in more total heat withdrawal than is desired, a condition referred to herein as "overchilling". For example, the evaporative benefit of increasing the evaporative rate from 20.8 to 24.0 gm/hr/m² may be desired, but at least some of the total heat withdrawal may not be. Such a condition can be mitigated by using a heater 64 to heat the chilled, demoisturized air prior to the step of supplying it to flowpath 30. As a practical matter, the heater would be operated only if it were determined that the temperature of the chilled air was, or would be, unsatisfactorily low. Referring again to FIG. 6B, the heating causes the temperature of the chilled, demoisturized air to increase from 16.8°C to a higher value, for example 19.0°C (hexagonal symbol). The heating step has no effect on the partial pressure of the water vapor in airstream 40, and hence no effect on the evaporative rate. However the temperature increase reduces the dry flux (in comparison to the dry flux at 16.8°C). Table 2 summarizes the change in performance parameters of the microclimate management system using air chilled to 16.8° compared to air reheated to 19.0°C. Table 3 presents a similar comparison relative to the use of unconditioned ambient air at 25.6°C and 75% RH.

TABLE 2

Parameter	Chilled to 16.8 °C	reheated to 19.0°C	Change
Temperature (°C)	16.8	19.0	2.2
ER (gm/hr/m²)	24.0	24.0	0
WF (watt/m²)	16.1	16.1	0
P_H2O (Pa)	1916	1916	0
DF (watt/m²)	64.0	56.7	-7.3
THW (watt/m²)	80.1	72.8	-7.3

TABLE 3

Parameter	Ambient Air	Chilled to 16.8°C and reheated to 19.0°C	Change
Temperature (°C)	25.6	19.0	-6.6
ER (gm/hr/m²)	20.8	24.0	3.2
WF (watt/m²)	14.0	16.1	2.1
P_H2O (Pa)	2451	1916	-535
DF (watt/m²)	34.7	56.7	22.0
THW (watt/m²)	48.7	72.8	24.1

FIG. 6B also shows one example in which no liquid phase perspiration is being deposited at the occupant/surface interface. The example assumes 90% relative humidity and a temperature of 36°C at the interface (quarter circle symbol). Accordingly, P_H2O,SKIN is about 5351 Pa. A calculation of wet flux capacity WFC would show a potential for 9.2 watts/m² of heat transfer. The corresponding calculation of evaporative capacity would show a potential to remove about 13.7 gm/hour/m² of moisture (perspiration) from the occupant/surface interface. However these values of heat transfer and evaporation can be realized only if dry heat transfer first reduces the temperature to about 34.1 °C (the temperature corresponding to 100% relative humidity at 5351 Pa).
FIG. 5B is a block diagram of an algorithm for enhancing evaporative capacity of an MCM-capable support surface beyond that which could be achieved with unconditioned ambient air. The numerical values to the right of the diagram blocks are from the above examples, using 36°C as the value for T_SKIN, and 5946 Pa, the vapor pressure of water at 36°C and 100% RH, as the value for P_H2O,SKIN. At block 100 the algorithm calculates P_H2O,AMBIENT, the partial pressure of water vapor at the prevailing ambient conditions, as a function of relative humidity and the vapor pressure of water, P_VAPOR, which is a function of ambient temperature, T_AMB: $PH 2 O, AMBIENT = (RH) (PVAPOR)$
P_VAPOR may be determined in any convenient way, for example by using a lookup table consistent with saturation line VP of FIG. 6B or by an equation, such as third order equation (9), which gives vapor pressure in pascals as a function of temperature in °C. Equation (9) models the saturation line satisfactorily between about 10°C and 40°C: $P_{VAPOR} = .0776 ({T_{AMB}}^{3}) - .757 ({T_{AMB}}^{3}) + 80.364 (T_{AMB}) + 413.15$
Block 102 uses equations (2) and (4) to calculate ER_AMBIENT, the evaporative rate achievable with ambient air, assuming the presence of perspiration to be evaporated at the skin / support surface interface.
Block 104 assess whether or not a desired value of evaporative rate input by a user by way of keypad 44 exceeds the evaporative rate achievable with the unconditioned ambient air. If not the controller takes a "corrective action" at block 106 such as commanding display panel 46 to display one or more messages such as a message to prompt the user for an alternate desired value, a message offering guidance as to what evaporative rate values are acceptable, or a message asking the user to confirm that the evaporative rate achievable with ambient air is satisfactory. After the user provides an acceptable, desired evaporative rate, for example 24 gm/hr/m², the algorithm proceeds to block 108.
At block 108 the algorithm uses equation (7B) to calculate P_{H2O,STREAM,REQUIRED}, the partial pressure of water vapor required to achieve the desired evaporative rate.
At block 110 the algorithm again uses a relationship between vapor pressure and T_{STREAM,REQUIRED}, temperature to determine the temperature required to achieve the P_{H2O,STREAM,REQUIRED} determined at block 108.
At blocks 112 and 114 the algorithm determines the difference ΔT between ambient temperature and the required temperature determined at block 110, and assesses whether or not the ΔT is within the known capability ΔT_MAX of the chiller. If not, the controller takes a "corrective action" 116 such as commanding display panel 46 to display one or more messages such as a message to prompt the user for an alternate desired value of evaporative rate, or a message offering guidance as to what evaporative rate values are achievable. After the user provides an acceptable desired evaporative rate, the algorithm repeats the appropriate steps starting at block 104, and proceeds to block 118.
At block 118, the controller causes chiller 60 to operate to chill the ambient air to the required temperature, T_{STREAM,REQUIRED}, determined at block 110.
At block 120 the controller determines if chilling the ambient air to the required temperature determined at block 110 would result in an overchill condition. The test for overchill can take various forms, for example a pre-emptive or corrective command from a user, or a predefined limit for a particular occupant, a particular class of occupants or a limit established by a facility protocol. If the overchill test is not satisfied, the algorithm proceeds to block 122. If the test is satisfied, the algorithm proceeds to block 124 where the controller causes heater 64 to operate to heat the chilled, demoisturized air. The algorithm then proceeds to block 122.

At block 122, the algorithm determines one or more microclimate performance parameters and causes the parameters to be displayed on display panel 46. Table 4 lists examples of parameters of possible interest along with their numerical values from the above example.

TABLE 4

Microclimate Performance Parameter	Example Value (Chill to 16.8°C without reheating)	Example Value (Chill to 16.8°C; reheat to 19.0°C)
Difference in evaporative rate attributable to the chilled, demoisturized air and the evaporative rate achievable with the unconditioned ambient air.	3.2	3.2
Ratio of the evaporative rate attributable to the chilled, demoisturized air and the evaporative rate achievable with the unconditioned ambient air;	1.2	1.2
Difference in wet flux attributable to the chilled, demoisturized air and the wet flux achievable with the unconditioned ambient air	2.1	2.1
Ratio of the wet flux attributable to the chilled, demoisturized air and the wet flux achievable with the unconditioned ambient air	1.2	1.2
Difference in dry flux attributable to the chilled, demoisturized air and the dry flux achievable with the unconditioned ambient air	29.3	22.0
Ratio of the dry flux attributable to the chilled, demoisturized air and the dry flux achievable with the unconditioned ambient air;	1.8	1.6
Difference in total heat withdrawal attributable to the chilled, demoisturized air and the total heat withdrawal achievable with the unconditioned ambient air;	31.4	24.1
Ratio of the total heat withdrawal attributable to the chilled, demoisturized air and the total heat withdrawal achievable with the unconditioned ambient air.	1.6	1.5

Referring again to FIG. 6B, the principles disclosed herein can be used to allow the user to manage the performance of an MCM-capable support by specifying a target total heat withdrawal, rather than by specifying an evaporative rate. If dry flux alone is sufficient to achieve the target total heat withdrawal, the chiller is operated to chill the ambient air (square symbol) to a temperature low enough to achieve the desired target heat withdrawal (e.g. the diamond symbol). This temperature is, by definition, higher than the temperature corresponding to 100% relative humidity.

If dry flux alone is not sufficient to achieve the target total heat withdrawal, the chiller is operated to cool the air to a temperature at least as low as that required to achieve 100% relative humidity (20.8°C) and also low enough to achieve the target total heat withdrawal (e.g. the domed symbol). Because achieving the target total heat withdrawal involves a wet flux component in addition to the dry flux component, the heat withdrawal will also cause airstream 40 to exert a drying influence on the bed occupant. If this results in excessive dryness, it may be desirable or necessary to sacrifice some of the wet flux. On the graph, an evaporative cooling limit is represented by limit 52, which is proportional to a predefined wet flux limit. Observance of the limit restricts operation of the chiller to achieving the total heat withdrawal at the wedge symbol. Table 5 shows example performance parameters of the system using ambient air (column 1), air chilled to achieve a total heat withdrawal of 58 watt/m² (column 2), air cooled to achieve a total heat withdrawal of 77 watt/m² (column 3) and air cooled to limit line 52 to achieve a total heat withdrawal of 67 watt/m² (column 4).

TABLE 5

	1	2	3	4
Parameter	Using Ambient Air	Chilled to Achieve THW = 58.0	Chilled to Achieve THW = 77.0	Observing 67.0 watt/m² THW (lower limit)
Temperature (°C)	25.6	22.8	17.6	20.2
ER (gm/hr/m²)	20.8	20.8	23.4	21.3
WF (watt/m²)	14.0	14.0	15.7	14.3
P_H2O (Pa)	2451	2451	2016	2367
DF (watt/m²)	34.7	44.0	61.3	52.7
THW (watt/m²)	48.7	58.0	77.0	67.0

In view of the foregoing, certain additional aspects of the method and system can be appreciated. For example the sequence in which certain steps of the algorithms may be changed. For example, a test for overchilling may be carried out after the chiller has chilled the ambient air, or it may be carried out prior to chilling, provided there is some foreknowledge of how much chilling qualifies as overchilling.
The foregoing numerical examples suggest that a caregiver would specify a desired numerical value of evaporative rate (mass per unit time per unit area) or total heat withdrawal (power per unit area). Alternatively, as seen in FIG. 8B, the user interface could present the user with a discrete scale extending from "0" to "10", a continuous scale extending from minimum evaporative rate or total heat withdrawal to a maximum evaporative rate or total heat withdrawal, or some other less technical means for specifying desired performance of the system.
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.

PART C

ABOVE BED SENSOR

BACKGROUND

The present disclosure is related to sensors for monitoring the position of a patient in a patient-support apparatus. More specifically, the present disclosure is related to monitoring patient movement in a patient-support apparatus with sensor that is spaced apart from the patient-support apparatus.
In a care environment such as a hospital, for example, the movement of patients is monitored for safety. For elderly patients and other patients who may be disoriented due to a medical condition or treatment, patient monitoring systems have been developed to alert a caregiver if the patient has exited their bed. In some instances, a sensor mat is used to determine the presence of the patient. Additional development of hospital beds with integrated scale systems has also resulted in systems that monitor the sensed weight to determine if the patient had exited the bed, and if so, to signal to a nurse call system of that condition.
Further development has resulted in additional integrated systems to monitor the amount of patient movement and alert a caregiver if a patient has begun to move. These systems are useful in predicting that an at-risk patient may be attempting to leave their bed. It is also useful to determine when a patient who is asleep or under anesthesia has awakened. More recently, the lack of patient movement has been monitored to determine the risk of development of decubitus ulcers or bed sores on the patient's skin due to immobility.
Other sensors have been employed to detect movement of patients to determine sleep patterns, detect seizures, or to detect incontinence. Such sensors are generally supported on or near a patient-support apparatus with cords or wires connecting the sensors to independent control systems for each detection system. The cords and wires must then be disconnected when the patient-support apparatus is moved from the room. In addition, the cords and wires present trip hazards and wire management issues in the patient room.

SUMMARY

The present application discloses 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:

According to one aspect of the present disclosure, a monitoring system for monitoring a patient in a patient-support apparatus comprises a detector, a standard, and a controller. The detector is operable to detect electromagnetic radiation within a detection field. The standard is positioned in the detection field and conveys electromagnetic radiation having a predetermined signature to the detector. The controller is coupled to the detector and includes a processor and a memory device coupled to the processor. The memory device includes instructions that, when executed by the processor, cause the controller to evaluate data received from the detector. The data received by the detector includes all of the electromagnetic radiation in the detection field. The electromagnetic radiation in the field is compared to the signature of the standard to determine if changes in the electromagnetic radiation are indicative of movement of a person in the detection field.

The memory device may also include instructions that, when executed by the processor, cause the controller to output a signal if the changes in the electromagnetic radiation are indicative that movement of a person in the detection field exceeds a threshold value. The signal may be output to a local alarm near the patient-support apparatus. In some embodiments, the system further includes a remote station that is spaced apart from the detection field and coupled to the controller, and wherein the signal is transmitted to the monitoring station. The local alarm or the remote station may each generate either a visual or an audible alarm. In some embodiments, both a visual and an audible alarm are generated.
In some embodiments the electromagnetic radiation detected by the detector is in the visible spectrum. In some embodiments the electromagnetic radiation detected by the detector is in the infra red spectrum. The system may further comprise a second detector operable to detect electromagnetic radiation within at least a portion of the detection field of the first detector. When present, the second detector is coupled to the controller. The memory device may further include instructions that, when executed by the processor, compare electromagnetic radiation received by the second detector to electromagnetic radiation received by the first detector and to the signature of the standard to determine if changes in the electromagnetic radiation detected by the first detector are indicative of movement of a person in the detection field. The memory device may further include instructions that, when executed by the processor, cause the controller to output a signal if the changes in the electromagnetic radiation sensed by both the first and second detector are indicative that movement of a person in the detection field exceeds a threshold value. The signal may be transmitted to the local alarm or the remote station. The controller may communicate wirelessly to the local alarm and the remote station, or the controller may have a hardwired connection to either the local alarm or the remote station.
The standard may be portable in some embodiments. The memory device may include instructions that, when executed by the processor, cause the system to determine a physical position of the portable standard. The physical position may define a datum and changes in the electromagnetic radiation detected by the detector may be compared to the datum to determine if the changes in the electromagnetic radiation are indicative of movement of a patient on the patient-support apparatus.
In some embodiments, the signature of the standard defines a datum and the system evaluates changes in electromagnetic radiation relative to the datum to determine if a patient on the patient-support apparatus has moved from an initial position.
In some embodiments, the system comprises a plurality of standards each having a predetermined signature. The memory device may include instructions that, when executed by the processor, cause the system to monitor changes in the position of each of the plurality of standards. The memory device may also include instructions that, when executed by the processor, cause the system to determine if one or more of the plurality of standards is in an unacceptable position. In some embodiments, the system generates a signal indicative of the unacceptable position and transmits the signal to a remote station spaced apart from the patient-support apparatus.
In some embodiments, the memory device includes instructions that, when executed by the processor, cause the system to evaluate the electromagnetic radiation to determine a location of a patient supported on the patient-support apparatus. The system may compare the location of the patient to the standards to determine if the patient is in an unacceptable position.
The position of the patient may be determined by determining a centroid of the patient. The centroid of the patient may be determined by weighting components of the thermal profile of the patient to determine a thermally weighted centroid.
According to another aspect of the present disclosure, a method of monitoring a position of patient in a patient-support apparatus includes monitoring electromagnetic radiation in a detection field, establishing a reference based on a standard in the detection field, and monitoring changes in the electromagnetic radiation in the detection field to determine if there is movement relative to the standard. The reference may be established based on a plurality of standards. The method may further include generating a notification if the movement relative to the standard exceeds a threshold. The notification may be generated proximate to the patient-support apparatus. The notification may be generated at a location spaced apart and separate from the patient-support apparatus. The position of the patient may be estimated by determining a centroid of the patient. The centroid of the patient may be determined by evaluating the thermal profile of the patient to determine a thermal centroid.
Additional features, which alone or in combination with any other feature(s), including those listed above and those listed in the claims, may comprise patentable subject matter and will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Fig. 1C is a perspective view of a patient supported in a supine position on a patient-support apparatus in hospital room with an sensor positioned above the patient-support apparatus such that the patient-support apparatus is positioned in the field of view of the sensor;
Fig. 2C is a top view of the patient-support apparatus of Fig. 1C;
Fig. 3C is a perspective view similar to Fig. 1C with articulated sections of the patient-support apparatus moved to place the patient reclined position with the patient's head and knees raised;
Fig. 4C is a top view of the patient-support apparatus in the position shown in Fig. 3C;
Fig. 5C is a top view similar to the top view of Fig. 2C, with the patient in Fig. 5C shown positioned closer to the foot end of the patient-support apparatus;
Fig. 6C is a diagrammatic representation of a patient-monitoring system; and
Fig. 7C is a diagrammatic representation of another embodiment of a patient-monitoring system.

DETAILED DESCRIPTION OF THE DRAWINGS

A patient monitoring system 10 includes a sensor 12 that is operable to detect electromagnetic radiation such as infrared radiation or light waves in the visible spectrum. The sensor 12 detects electromagnetic radiation in a field of view 14 which defines a detection zone. The electromagnetic radiation received by a detector 16 in the sensor 12 with optical elements such as lenses and filters as is well known in the art focusing the electromagnetic radiation. In the illustrative embodiment of Fig. 1C, the sensor 12 is positioned on a ceiling 22 of a patient room 18. The detection zone 14 of the sensor 12 is positioned in a known location such that a patient-support apparatus 20 may be positioned in the patient room 18 so that the electromagnetic radiation in the area of the patient-support apparatus 20 is detected by the sensor 12.
As shown in Figs. 1C and 2C, the patient-support apparatus 20 includes a number of barrier elements including a patient-right head siderail 26, a patient-left head siderail 28, a patient-right foot siderail 30, and a patient-left foot siderail 32. In addition, the patient-support apparatus may include a headpanel 34 and a footpanel 36. The patient-support apparatus 20 includes a number of support sections including an articulated head section 38 pivotable relative to an intermediate frame 46. An articulated thigh section 42 is also pivotable relative to the intermediate frame 46 and an articulated foot section 44 is pivotable relative to the thigh section 42. The support sections are supported on the intermediate frame 46 and the articulated sections 38, 40, 42. The intermediate frame 46 is supported above a base frame 48 and movable relative to the base frame 48 by a lift system 50 as is well known in the art.
A number of standards 62, 64, 66, 68, 70, and 72 are positioned on various elements of the patient-support apparatus 20 so that references points may be established on the patient-support apparatus 20. The standards 62, 64, 66, 68, 70, and 72 are configured to reflect a particular wavelength of light when illuminated so that the system 10 may identify the standards 62, 64, 66, 68, 70, and 72 by the reflected wavelength. In the alternative, the standards 62, 64, 66, 68, 70, and 72 may reflect widely varying wavelengths in a relatively small or clustered area such that the system 10 can discriminate the cluster of varying wavelengths from the environment in the patient room 18 to determine the location of a particular one of the standards 62, 64, 66, 68, 70, and 72. In still other embodiments, the standards 62, 64, 66, 68, 70, and 72 may be an electromagnetic radiation emitter that generates a particular radiation signature which may be discriminated by the system 10 to determine the position of the standards 62, 64, 66, 68, 70, and 72.
Referring now to Fig. 2C, a first standard 62 is shown to be positioned on the headpanel 34 and a second standard 64 is positioned on the footpanel 36 with each of the standards 62 and 64 being centered on the respective panels. The standards 62 and 64 define a longitudinal axis 52 of the patient-support apparatus 20 which may be utilized by the system 10 when the system 10 is evaluating electromagnetic radiation in the field 14.
The longitudinal axis 52 serves as a datum against which movement detected by the system 10 is compared to make determinations as to whether the detected movement exceeds a predetermined threshold or is of such a magnitude that it may be indicative of certain characteristics of the patient 40 supported on the patient-support apparatus 20. The standards 66, 68, 70, 72 form the vertices of a four sided polygon 54 that is detected by the system 10. The position of the patient 40 supported on the patient-support apparatus 20 may also be compared to the polygon 54 to determine if the patient 40 is outside of an acceptable position on the patient-support apparatus 20. In addition, the standards 66, 68, 70, 72 also allow the system 10 to determine if the respective side rails 26, 28, 30, 32 are in a raised or lowered position. In the illustrative embodiment of the present disclosure, the side rails 26, 28, 30, 32 are spaced laterally inwardly toward the axis 52 when the side rails are in a lowered position as compared to the lateral position in a raised position. Referring now to Fig. 4C, it can be seen that the side rails 26, 30 on the patient right side of the patient-support apparatus 20, which are in a raised position, are positioned such that the standards 66, 70 positioned on the side rails 26, 30 respectively, are spaced away from the longitudinal axis 52 by a distance X. In contrast, the side rails 28, 32 on the patient left side of the patient-support apparatus 20, which are in a lowered position, results in the standards 68, 72 being spaced away from the longitudinal axis 52 by a distance Y which is less than X. The system 10 compares the positions of the standards on the respective side rails to the longitudinal axis 52 to determine if each of the side rails is in a raised or lowered position.
In the illustrative embodiment, the polygon 54 is detected from an overhead position. Because the head and side rails 26, 28 move with the head section 38, while the foot side rails 30, 32 are fixed to the intermediate frame 46, raising of the head section 38 results in a change in the dimensions of the polygon 54 as viewed by the sensor 12. Comparing the polygon 54 in Fig. 4C to the polygon 54 in Fig. 5C, it can be seen that when the head section 38 is raised as in Fig. 4C, a length dimension 56 of the polygon 54 is reduced. By monitoring the changes in the position of the standards and changes in the dimensions between the standards, the system 10 is able to discern changes in the position of the sections 38, 40, 42, 44 and frames 46, 48 of the patient-support apparatus 20. Comparing the information concerned about the position of the patient-support apparatus 20 members, to a detected position of a patient 40 supported on the patient-support apparatus 20, the system can determine if the patient 40 is moving or is out of acceptable position on the patient-support apparatus 20.
As described earlier, the sensor 12 includes a detector 16. In the illustrative embodiment, the detector 16 is a charge coupled device (CCD) capable of receiving an image from the detection zone 14. In the illustrative embodiment, the detector 16 operates in the visible spectrum and compares an initial image of the patient 40 and patient-support apparatus 20 changes in the image over time to discern how a patient 40 has changed position over time. If the patient's position has changed sufficiently to indicate and unacceptable position, the system 10 will generate an alarm which may be visual or audible in the patient room 18, or it may be transmitted to a monitoring station 58 in the patient room 18 as indicated in Figs. 6C and 7.
To detect movement of the patient 40, the system 10 must evaluate changes in a characteristic of the patient 40. Each person has a center of mass 60 which is generally located in the torso. According to the present disclosure, the center of mass 60 is estimated by determining the centroid of the portion of the patient 40 visible to the sensor 12. In one illustrative embodiment, the centroid 60 of the patient 40 is determined using geometric decomposition. The centroid of multiple simple shapes detected by the system 10 is first determined, and then the positions of each of the centroids of the simple shapes are averaged, weighted by the area of the simple shape used for each centroid. By continuously recalculating the centroid 60 of the patient 40, changes in the position of the centroid 60 may be used to determine if the patient 40 is properly positioned or is moving in a manner which indicates the patient 40 will attempt to exit the patient-support apparatus 20. In the visible spectrum, the analysis requires the system t10 to determine what in the detection zone 14 can be properly assigned to being a portion of the patient 40 and what in the view is environment. To overcome the difficulty in detecting the centroid 60 of an immobile patient 40, the system 10 may be taught the location of the centroid 60 by a user who positions a movable standard 74 on the patient's torso and synchronizing the position of the standard 74 with the system 10. The system 10 then monitors the area around the taught centroid 60 to determine if the patient 40 has moved relative to the fixed standards on the patient-support apparatus 20. In other embodiments, the movable standard 74 may be attached to the patient 40 so that movement of the patient 40 results in movement of the standard 74, which approximates the centroid of the patient 40.
In another embodiment, the detector 16 is configured to detect electromagnetic radiation in the infrared spectrum. This significantly simplifies the the determination of the centroid 60 of the patient 40. In the infrared embodiment, the system 10 is configured to accept that any electromagnetic radiation in the field of view that indicates a temperature of greater than a predetermined threshold, such as 85°F, for example, is assumed associated with the patient 40. Once an area is sensed to be associated with the patient 40, a centroid 60 may be determined based simply on an average position of the areas associated with the patient 40. For additional accuracy, the centroid may be weighted by both position and temperature so that a heat based centroid may be determined. Movement of the centroid 60 of the patient 40 relative to the standards 62, 64, 66, 68, 70, and 72 is then monitored by the system 10 to monitor the patient's movement.
In use, the system 10 may compare the position of the patient 40 to the standards 62, 64, 66, 68, 70, and 72 to determine that the patient 40 has moved to a position in which the patient 40 is at risk for injury. For example, in Figs. 3C and 4C, the patient 40 is shown to have migrated toward the footpanel 36 so that the patient's back is being supported by the thigh section 42 and the patient 40 is in an improper position. For example, the centroid 60 of the patient 40 in Figs. 3C and 4C is positioned outside of the polygon 54 and is spaced away from the polygon 54 by a distance Z. The system 10 may alert a caregiver that the patient 40 is out of position and should be re-positioned to the optimal position.
Similarly, the patient 40 is shown to be migrated to the patient-right side of the patient-support apparatus 20 in Fig. 5C. After determining that the centroid 60 is spaced apart from the axis 52, the system 10 may send signal indicative that the patient 40 is out of position, resulting in an alarm either in the room 18 or at the remote station 58. It should also be noted that the shape of the polygon 54 may be used to determine if one or more siderails 26, 28, 30, or 32 are in a lowered position. Again referring to Fig. 5C, it is shown that when the patient-left head siderail 28 is in a lowered position and the head section 38 is raised, the polygon 54 has an irregular shape and the standard 68 is positioned closer to the headpanel 34 than the standard 66, thus indicating that the siderail 28 is in a lowered position.
While the forgoing description explains the use of multiple standards, it should be understood that the system 10 may detect positioning or movement of a patient 40 with respect to a single standard, such as standard 62, for example. In one embodiment, the standard 62 positioned on the headpanel 34 defines a fixed position and is indicative of an orientation defining the axis 52. Movement of the centroid 60 relative to the standard 62 and axis 52 provides sufficient information for the system 10 to determine if the patient 40 is moving relative to the patient-support apparatus 20 or if the patient 40 is in an unacceptable position such as that shown in Figs. 3C and 4C or Fig. 5C.
In another embodiment, a patient monitoring system 110 may include multiple detectors 16, 116 as shown in Fig. 7C. Each of the detectors 16, 116 may be positioned in different known locations on the ceiling 22 with the detectors 16, 116 each configured to have the same detection zone 14. The system 110 may then process data from each of the detectors 16, 116, comparing the data from each of the different detectors 16, 116 to determine information about the patient 40 and position of the members of the patient-support apparatus 20. In some embodiments, one sensor 12 may have a detector 16 used to detect electromagnetic radiation in the visible spectrum and a second sensor 12 may have a detector 116 electromagnetic radiation in the visible spectrum to provide additional data on movement in the field of view 14. It should be understood that while the illustrative embodiment of Fig. 7C shows two detectors 16, 116, other embodiments may include additional sensors 12 each with an associated detector 16 with the system utilizing data from all of the sensors 12 to determine information about the patient 40 or patient-support apparatus 20 in the detection zone 14.
Each system 10, 110 includes at least one sensor 12, and one or more standards 62, 64, 66, 68, 70, and 72, and a controller 80. Each of the systems 10, 110 may optionally include a movable standard 74. The controller 80 includes a processor 82 and a memory device 84. The processor 82 utilizes data and algorithms stored in memory 84 to analyze data from the sensor 12 as described above. In some embodiments, the controller 80 will monitor the location of the patient 40 relative to the standards 62, 64, 66, 68, 70, and 72 so that the location of the patient 40 relative to the members of the patient-support apparatus 20 is monitored. In some embodiments, the controller 80 will indicate an alarm condition to a local alarm 86 positioned in the room 18. The local alarm 80 may provide either a visual indication of the alarm condition or an audible indication of the alarm condition, or both a visual and audible indication. The controller 80 may also provide a signal to the remote station 58 and the remote station 58 will generate an indication of the alarm condition at the location of the remote station 58. The remote station 58 is positioned apart from the patient room 18 so that a caregiver in a remote location is apprised of the alarm condition. The controller 80 may communicate with the local alarm 86 ore remote station 58 through either a hard-wired connection or a wireless connection. The remote station 58 may generate either an audible or visual indication of the alarm condition, or both an audible and visual indication.
In some embodiments, one of the standards 62, 64, 66, 68, 70, and 72 may provide a signal to the sensor 12 that is indicative of the specific patient-support apparatus 20 in the field 14. The sensor 12 may then identify the specific patient-support apparatus 20 identification to the remote station 58 such that a hospital information system in communication with the remote station 58 may associate the specific patient-support apparatus 20 to the specific room 18.
The system 10 may also monitor the standards 62, 64, 66, 68, 70, and 72 to determine the position of various members of the patient-support apparatus 20 and provide the position data to the hospital information system through the remote station 58. For example, the system 10 may monitor siderail position, bed elevation, articulated section positions, the amount of tilt of the intermediate frame. It should be understood that while the standards 62, 64, 66, 68, 70, and 72 are shown to be positioned on specific members of the patient-support apparatus 20 in the illustrative embodiment, other standards may be positioned on various members of the patient-support apparatus 20 such that one or more sensors 12 may monitor the location of the various standards, and thereby, members to monitor the position of the position of the members of the patient-support apparatus 20.
It is also contemplated that the system 10 may be used to monitor other characteristics of the patient 40 for vigilance monitoring. For example, by monitoring cyclical changes in position, the system 10 may monitor the respiration rate of a patient 40 on patient-support apparatus 20. Changes in the temperature profile of the patient 40 may also be used to detect incontinence of the patient. Still also, the system 10 may detect the patient's body temperature.
Although certain illustrative embodiments have been described in detail above, variations and modifications exist within the scope and spirit of this disclosure as described and as defined in the following claims.

PART D

PERSON-SUPPORT APPARATUS

BACKGROUND OF THE DISCLOSURE

This disclosure relates generally to person-support apparatuses. More particularly, but not exclusively, one illustrative embodiment relates to a person-support apparatus with fluid tank receptacle.
Person-support apparatuses in hospitals can often have fluid tanks coupled thereto that can be used to supply fluid to a person supported on the person-support apparatus. While various devices have been developed, there is still room for development. Thus a need persists for further contributions in this area of technology.

SUMMARY OF THE DISCLOSURE

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.
One illustrative embodiment of the present disclosure can include fluid tank receptacle with a cage configured to extend from the upper frame a first distance to support a fluid tank when it is positioned in the fluid tank receptacle and retract toward the upper frame such that the cage is a second distance from the upper frame that can be less than the first distance when the fluid tank is not positioned in the fluid tank receptacle. Another illustrative embodiment of the present disclosure can include an upper frame with an upper frame base supporting a deck with a seat section having stationary side portions coupled to the upper frame base and movable middle portions positioned between the stationary side portions that can be configured to cooperate with a head deck section and a foot deck section to move the upper frame between a substantially horizontal position and a chair position.
Additional features alone or in combination with any other feature(s), including those listed above and those listed in the claims and those described in detail below, can comprise patentable subject matter. Others will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the illustrative examples in the drawings, wherein like numerals represent the same or similar elements throughout:

Fig. 1D is a perspective side view of a person-support apparatus according to one illustrative embodiment with the upper frame in a substantially horizontal orientation and including a fluid tank receptacle.
Fig. 2D is a perspective side view of a person-support apparatus according to one illustrative embodiment with the upper frame in a chair position.
Fig. 3D is a perspective side view of the fluid tank receptacle of Fig. 1D.
Fig. 4D is a cross-sectional side view of the .fluid tank receptacle of Fig. 1D showing the cage in a use position.
Fig. 5D is a perspective side view of the fluid tank receptacle of Fig. 1D showing a fluid tank received in the fluid tank receptacle.
Fig. 6D is a perspective side view of the fluid tank receptacle of Fig. 1D showing the accessory pole receptacle and transport handle.
Fig. 7D is a perspective side view of the fluid tank receptacle of Fig. 1D showing the cage in the use position.
Fig. 8D is a perspective side view of the fluid tank receptacle of Fig. 1D showing the cage in the use position.
Fig. 9D is a perspective top view of the fluid tank receptacle of Fig. 1D.
Fig. 10D is a perspective bottom view of the fluid tank receptacle of Fig. 1D
Fig. 11D is a partial cross-sectional view of the fluid tank receptacle of Fig. 1D showing the spring located in the slots in the housing at a first length when the cage is in a storage position.
Fig. 12D is a partial cross-sectional view of the fluid tank receptacle of Fig. 1D showing the spring located in the slots in the housing at a second length as the cage moves toward the use position.
Fig. 13D is a partial cross-sectional view of the fluid tank receptacle of Fig. 1D showing the spring located in the slots in the housing at a third length when the cage is in the use position.
Fig. 14D is a perspective top view of the deck of Fig. 1D showing the first and second movable portions and first and second stationary portions.
Fig. 15D is a perspective side view of the deck of Fig. 1D showing the first and second movable portions in a first orientation with respect to the upper frame as the person-support apparatus moves to a chair position.
Fig. 16D is a perspective end view of the deck of Fig. 1D showing the first and second movable portions in a first orientation with respect to the upper frame as the person-support apparatus moves to a chair position.

DETAILED DESCRIPTION OF THE DRAWINGS

While the present disclosure can take many different forms, for the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. No limitation of the scope of the disclosure is thereby intended. Various alterations, further modifications of the described embodiments, and any further applications of the principles of the disclosure, as described herein, are contemplated.
One illustrative embodiment of the present disclosure can include fluid tank storage assembly with cage configured to extend from the upper frame a first distance when a fluid tank is stored in the fluid tank storage assembly and retract toward the upper frame such that the cage is a second distance from the upper frame that can be less than the first distance when the fluid tank is not stored in the fluid tank storage assembly. Another illustrative embodiment of the present disclosure can include an upper frame with an upper frame base supporting a deck with a seat section having stationary side portions coupled to the upper frame base and movable middle portions positioned between the stationary side portions that can be configured to cooperate with a head deck section and a foot deck section to move the upper frame between a substantially horizontal position and a chair position.
A person-support apparatus 10 according to one illustrative embodiment of the current disclosure is shown in Figs. 1D-16D. The person-support apparatus 10 can be a hospital bed with a first section F1 or head support section F1, where the head of a person (not shown) can be positioned and a second section S1 or a foot support section S1, where the feet of the person (not shown) can be positioned. It should be appreciated that the person-support apparatus 10 can also be a hospital stretcher or an operating table. The person-support apparatus 10 can define a first longitudinal axis X1 passing through the first section F1 and the second section S1 and a transverse axis Y1 substantially perpendicular to the first longitudinal axis. It should be appreciated that the first longitudinal axis X1 and the transverse axis Y1 can be in the same horizontal plane. The person-support apparatus 10 can include a lower frame 12 or base 12, a plurality of supports 14 coupled with the lower frame 12 and an upper frame 16 movably supported by the plurality of supports 14 above the lower frame 12. It should be appreciated that the supports 14 can be lift mechanisms 14 that can move the upper frame 16 with respect to the lower frame 12. It should also be appreciated that in one illustrative embodiment, the person-support apparatus 10 can support a person-support surface 18 on the upper frame 16.
The upper frame 16 can include an upper frame base 20, a deck 22, siderails 24, endboards 26, and an accessory support 28 as shown in Figs. 1D-2D, 5D-8D, and 14D-16D. The upper frame base 20 can be coupled with the supports 14 and can support the deck 22 thereon as shown in Figs. 1D and 2D. The accessory support 28 can be located at a head end 30 of the upper frame 16. It should be appreciated that the accessory support 28 can be located at a foot end 32 of the upper frame 16. The accessory support 28 can include transport handles 34, accessory pole receptacles 36, and fluid tank receptacles 38 as shown in Figs. 1D-13D. It should be appreciated that accessory poles 40, such as, for example, IV poles and/or line management devices, can be secured to the accessory support 28. The transport handles 34 can be configured to be gripped by a person and pushed to move the person-support apparatus 10 from one location to another. The accessory pole receptacles 36 can be configured to removably retain accessory poles, such as, IV poles and/or line management equipment. It should be appreciated that the transport handles 34 can include a curved portion 44 that can be configured to at least partially surround a portion of an accessory pole 40 received in the accessory pole receptacles 36.
The fluid tank receptacle 38 can include a receptacle body 46 with an opening 48 therethrough, a bumper 50, a retainer 52, and a cage 54 as shown in Figs. 1D-13D. The opening 50 can be sized to receive a fluid tank 56, such as, for example, an oxygen tank, therein. The retainer 52 can be secured to the receptacle body 46 and can be configured to couple the cage 54 to the receptacle body 46 and movably couple the bumper 50 to the receptacle body 46. The retainer 52 can include a plurality of holes 58 that can be configured to receive a portion of the cage 54 and fasteners used to secure the retainer 52 to the receptacle body 46.
The bumper 50 can be configured to absorb some of the force generated when the bumper 50 collides with an object, such as, for example, a wall. In one illustrative embodiment, the bumper 50 can be positioned between the receptacle body 46 and the retainer 52 as shown in Figs. 1D-13D. The bumper 50 can be configured to rotate about a rotational axis R1 passing through the center of the opening 48. It should be appreciated that the ability of the bumper 50 to rotate can help reduce the force generated when the bumper 50 indirectly collides with an object, such as, a wall.
The cage 54 can be movably coupled to the receptacle body 46 and can be configured to move between a use position where the cage 54 supports a fluid tank 56 received within the fluid tank receptacle 38, and a storage position. The cage 54 can include a plurality of cage supports 60, a support coupler 62, and a plurality of springs 64. The cage supports 60 can include a first support end 66 and a second support end 68. The first support end 66 can be configured to pass through one of the holes 58 in the retainer 52 to slidably engage one of the cage support slots 70 in the receptacle body 46. The second end 68 can be configured to be coupled to the support coupler 62. It should be appreciated that the cage supports 60 can be U-shaped and the second end 68 can pass through another of the holes 58 to engage another of the cage support slots 70. The first support end 66 can include a retaining ring 72 coupled thereto and configured to cooperate with the spring 64 and/or the retainer 52 to maintain the first support end 66 within the cage support slot 70.
The spring 64 can be located in the cage support slot 70 and can be configured to bias the cage 54 toward the storage position. The spring 64 can be positioned between the retaining ring 72 and the retainer 52 as shown in Figs. 11D-13D. The spring 64 can be a first length when the cage 54 is in the storage position as shown in Fig. 14D and can be compressed to a second length when a fluid tank 56 engages the cage 54 and moves the cage 54 to the use position as shown in Fig. 16D. It should be appreciated that the weight of the fluid tank 56 can cause the spring 64 to compress. When the fluid tank 56 is removed, the spring 64 can bias the cage 54 toward the storage position.
The deck 22 can include a head portion 74, a seat portion 76, and a foot portion 78 as shown in Figs. 1D-2D and 14D-16D. The head portion 74, the seat portion 76, and the foot portion 78 can be movably coupled with each other and/or the upper frame base 20 and can be configured to cooperate with one another to move the deck 22 between a relatively horizontal position and a chair position as shown in Figs. 2D and 16D. The seat portion 76 can include first and second outer portions 80 and 82 and first and second inner portions 84 and 86. The first and second inner portions 84 and 86 can be positioned between the first and second outer portions 80 and 82. The first and second inner portions 84 and 86 can be movable with respect to the upper frame base 20. In one illustrative embodiment, the first inner portion 84 can be movably coupled to the second inner portion 84 at a first joint 88 and the second inner portion can be coupled to the foot portion 78 at a second joint 90. The first and second outer portions 80 and 82 can be stationary with respect to the upper frame base 20. It should be appreciated that the first and second outer portions 80 and 82 can help reduce incidents of pinch points and maintain the spacing between the deck 22 and the siderails 24 as the first and second inner portions 84 and 86 move with respect to the upper frame base 20.
Many other embodiments of the present disclosure are also envisioned. For example, a person-support apparatus comprises a lower frame, an upper frame, and a deck. The upper frame is movably supported above the lower frame by a support. The deck is supported on the upper frame, the deck includes a section with a first portion configured to be movable with respect to the upper frame and a second portion configured to be stationary with respect to the upper frame. The person-support apparatus is configured to be movable between a generally horizontal position and a chair position.
In another example, a fluid tank receptacle comprises a housing, a cage, and a retainer. The housing includes an opening therethrough configured to receive a fluid tank. The cage movably engages the housing and configured to support the fluid tank. The retainer is coupled to the housing and is configured to movably retain a portion of the cage within the housing such that the cage is able to move between a storage position and a use position with respect to the housing.
Any theory, mechanism of operation, proof, or finding stated herein is meant to further enhance understanding of principles of the present disclosure and is not intended to make the present disclosure in any way dependent upon such theory, mechanism of operation, illustrative embodiment, proof, or finding. It should be understood that while the use of the word preferable, preferably or preferred in the description above indicates that the feature so described can be more desirable, it nonetheless can not be necessary and embodiments lacking the same can be contemplated as within the scope of the disclosure, that scope being defined by the claims that follow.
In reading the claims it is intended that when words such as "a," "an," "at least one," "at least a portion" are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language "at least a portion" and/or "a portion" is used the item can include a portion and/or the entire item unless specifically stated to the contrary.
It should be understood that only selected embodiments have been shown and described and that all possible alternatives, modifications, aspects, combinations, principles, variations, and equivalents that come within the spirit of the disclosure as defined herein or by any of the following claims are desired to be protected. While embodiments of the disclosure have been illustrated and described in detail in the drawings and foregoing description, the same are to be considered as illustrative and not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Additional alternatives, modifications and variations can be apparent to those skilled in the art. Also, while multiple inventive aspects and principles can have been presented, they need not be utilized in combination, and various combinations of inventive aspects and principles are possible in light of the various embodiments provided above.

PARTE

VARIABLE HEIGHT SIDERAIL

TECHNICAL FIELD

The subject matter described herein relates to siderails of the type used on hospital beds and particularly to a siderail having a variable height that enables the siderail to comply with potentially conflicting design requirements.

BACKGROUND

Beds of the type used in hospitals, other health care facilities and home health care settings include a frame, a deck, a mattress resting on the deck and a set of siderails. The siderails have a deployed or raised position and a lowered or stored position. In the deployed position the top of the siderail should be a minimum distance above the top of the deck, and the bottom of the siderail should be low enough, and close enough to the neighboring lateral side of the deck, to ensure that any gap between the siderail and the deck is less than a specified amount, for example 60 mm. In the stowed position, the top of the siderail should be a minimum distance below the top of the mattress to facilitate occupant ingress and egress, and the distance from the bottom of the siderail to the floor should be no less than a prescribed amount, for example 120 mm. A siderail tall enough to satisfy the requirements of the deployed state may be too tall to satisfy one or both of the requirements of the stored state. Conversely, a siderail short enough to satisfy the requirements of the stored state may be too short to satisfy one or both of the requirements of the deployed state.
Siderails should also be designed to minimize "pinch points", i.e. spaces large enough to receive a foreign object when the siderail is in one position, but which become small enough to trap the object when the siderail is placed in a different position.

SUMMARY

A siderail comprises a rail having a lower edge extending longitudinally from a head end to a foot end, and a longitudinally outer link comprising a head side outer link segment and a foot side outer link segment. Each segment is connected to the rail at a joint OR and connected to a host frame at a joint OF. The siderial also includes an inner link longitudinally intermediate the outer link segments and connected to the rail at a joint IR and to the host frame at a joint IF. The head side outer link segment extends longitudinally from approximately the head end of the rail lower edge toward the inner link without longitudinally overlapping the inner link. The foot side outer link segment extends longitudinally from approximately the foot end of the rail lower edge toward the inner link without longitudinally overlapping the inner link.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the various embodiments of the siderail described herein will become more apparent from the following detailed description and the accompanying drawings in which:

FIG. 1E is a right side elevation view of a hospital bed having variable height siderails as described herein.
FIG. 2E is a plan view of the bed of FIG. 1E.
FIG. 3E is a perspective view of the right side, head end siderail of FIG. 1E in a raised or deployed state as seen from the non-occupant side of the siderail.
FIG. 4E is a view similar to that of FIG. 3E with the siderail in a lowered or stored state.
FIG. 5E is a side elevation view of the left side head end siderail as seen from the occupant side of the siderail.
FIG. 6E is an exploded, perspective view of the siderail of FIG. 6E as seen from the occupant side of the siderail.
FIGS. 7E-10E are a sequence of perspective views of the siderail of FIG. 5E as seen from the occupant side of the siderail showing the siderail in a deployed position, a partially lowered position, a more lowered position, and a stored position respectively.
FIG. 11E is a view similar to that of FIG. 3E showing a variable height siderail in which an outer link portion thereof is constructed of two pieces, the siderail being shown in a deployed position.
FIG. 12E is a view similar of the siderail of FIG. 11E showing the siderail in a stored position.
FIG. 13E is a view similar to that of FIG. 1E showing other embodiments of the variable height siderail.
FIG. 14E is a perspective view of the head end siderail of FIG. 13E.

DETAILED DESCRIPTION

Referring to FIGS. 1E-2E, a hospital bed 10 having a longitudinally extending centerline 20 extends longitudinally from a head end 12 to a foot end 14 and laterally from a left side 16 to a right side 18. The bed includes a base frame 26 and an elevatable frame 28 mounted on the base frame by interframe links 30. The elevatable frame includes a deck 32. A mattress 34 rests on the deck. Casters 38 extend from the base frame to the floor 40.
The bed also includes left and right head end siderails 50, 52 and left and right foot end siderails 54, 56. The head end siderails are substantially mirror images of each other. Similarly, the foot end siderails are substantially mirror images of each other. Each head end siderail differs from its neighboring foot end siderail, however the differences do not extend to the variable height attribute described herein. Accordingly it will suffice to describe only one siderail in detail.
Referring to FIGS. 3E-10E, right side head end siderail 52 includes a rail 70 having a lower edge 72 extending longitudinally from a rail head end 74 to a rail foot end 76, thereby defining the longitudinal extent L of the lower edge. A longitudinally outer link 80 comprises a head side outer link segment 82 and a foot side outer link segment 84. Each outer link segment is connected to the rail at joints OR and to the host frame 28 at joints OF. An inner link 110 having a laterally outer side 112, a laterally inner side 114, a head side edge 116 and a foot side edge 118 resides longitudinally intermediate the outer link segments 82, 84. The inner link is connected to rail 70 at a joint IR and to host frame 28 at a joint IF. The joints IR, OR, IF, and OF define pivot axes IRx, ORx, IFx, OFx that extend parallel to centerline 20. Joints IR and OR are laterally displaceable relative to the frame such that rail 70, outer link 80, inner link 110 and frame 28 comprise a four bar linkage enabling movement of the rail between a deployed or raised position (FIGS. 3E, 5E, 7E-9E) and a stored or lowered position(FIGS. 4E, 10E). The progression from the deployed position to the stowed position is seen best in the sequence of views of FIGS. 7E-10E.
Each outer link segment 82, 84 has a frame end 88, a rail end 90 and an elbow portion 92 extending between the frame and rail ends. The frame end 88 of each segment is connected to frame 28 at joints OF. The frame end 88 of each outer link segment has a longitudinally inboard edge 96 and a longitudinally outboard edge 98, the longitudinally inboard edge 96 being longitudinally closer to inner link 110, and the longitudinally outboard 98 edge being longitudinally further away from the inner link. The rail end 90 of each outer link segment extends from joint OR in a direction nonparallel to that of the frame end 88. For example, when the siderail is in the deployed state as seen in FIG. 7E, the frame end 88 of each outer link segment is oriented approximately horizontally while the rail end 90 is oriented substantially vertically. The rail end of each outer link segment includes a wing portion 94 having a top edge 106.
The rail ends 90 of the outer link segments extend longitudinally toward the inner link, but not far enough to overlap the inner link, even partially. In the illustrated siderail, the rail end of the head side outer link segment 82 extends longitudinally from approximately the head end 74 of the rail lower edge, toward the inner link, and terminates at a terminus 100 longitudinally outboard of the inner link. The rail end of the foot side outer link segment 84 extends longitudinally from approximately the foot end 76 of the rail lower edge toward the inner link, and terminates at a terminus 102 also longitudinally outboard of the inner link. In the limit, terminus 100 of the head side outer link segment 82 would be no further inboard than the head side edge 116 of inner link 110, and terminus 102 of the foot side outer link segment 84 would be no further inboard than the foot side edge 118 of inner link 110.
The rail end 90 of each outer link segment 82, 84, in addition to being connected to rail 70 at a joint OR, is also connected to rail 70 at a joint P near the longitudinal ends 74, 76 of the rail. Joint P is a joint between the rail 70 and the wing portion 94 of rail end 90 of each link segment. Joint P defines a pivot axis Px which is common with pivot axis ORx of joint OR.
Rail end 90 of each outer link segment has a top edge 106 spaced from rail lower edge 72 along substantially all of the longitudinal extent of the rail end of the outer link thereby defining interedge space 130. The presence of inter-edge space 130 addresses a pinch risk that would be formed by edges 72, 106 if they were separated by a smaller distance. In the illustrated siderail any pinch risk is limited to the regions 132 where the wing portions 94 are in close proximity to the rail in order to be connected thereto at joint P. The space also facilitates cleaning. A larger space 130 will be more advantageous for limiting pinch risk and facilitating cleaning; a smaller space will be less advantageous. The size of space 130 may be determined by the siderail designer or prescribed by regulation or voluntary standards. As is evident from FIGS. 7E-10E, adequate inter-edge spacing is maintained throughout the range of travel of the rail from deployed to stored.
In the deployed state (e.g. FIG. 7E) the rail end of each outer link, including wing portion 94, extends substantially vertically relative to the rail. Consequently the siderail 52 has an effective height h_UP defined by a height h₁ of the rail and a height h₂ of the rail end of the outer link segments. As the siderail is lowered (FIGS. 8E, 9E) to a fully stored state (FIG. 10E or FIG. 4E) the rail end of each outer link panel, including wing porton 94, folds up laterally inwardly of the rail (i.e. behind the rail). Consequently, the siderail, when in the stored state, has an effective height h_DOWN which is less than h_UP. In the illustrated embodiment, no part of the outer link segments 82, 84 projects vertically below lower edge 72 of the rail when the siderail is in the stored state. Accordingly, the outer link segments make no contribution to the height h_DOWN. The larger effective height h_UP when the siderail is deployed, combined with the smaller effective height h_DOWN when the siderail is stored, enables the siderail to meet the potentially conflicting design requirements of the deployed and stored states. In addition, the smaller effective height h_DOWN provides additional latitude for a bed occupant to position his heels under his center of gravity, which is desirable when a bed occupant is moving out of or into the bed by way of a sitting position with his or her legs draped over the side of the bed. The smaller effective height also offers an improved line of sight and access to foot pedal controls, such as foot pedals 42 (FIG. 1E).
In the embodiment of FIGS. 1E-10E each outer link segment is illustrated as a one piece structure. However it is expected that in practice each outer link segment would be a two piece structure. Referring to FIG. 11E the two piece structure comprises an arm 140 extending between joints OF and OR and a separately manufactured panel 94', analogous to wing portion 94 of the single piece construction, affixed to arm 140 by fasteners 142. Such a construction allows the designer to specify the use of different materials best suited for the demands placed on the arm and panel portions of the outer link segments.
The above mentioned two piece construction leads to an alternative interpretation in which a siderail 52' comprises a rail 70' having an upper panel 70 and a lower panel 94'. The upper panel lower edge 72 extends longitudinally from upper panel head end 74 to upper panel foot end 76. The siderail also includes longitudinally outer link 80 comprising head side outer link segment 82 and foot side outer link segment 84. Each outer link segment comprises the arm 140 comprising frame end, rail end and elbow portions 88, 90, 92 respectively, and the separately manufactured panel 94' affixed to its rail end by fasteners 142. The siderail also includes inner link 110 longitudinally intermediate the outer link segments. The inner link is connected to the upper panel 70 at joint IR and to the host frame 78 at joint IF.
The rail lower panel 94 comprises head side and foot side subpanels 94'H, 94'F, each of which is connected to one of the outer link segments by the fasteners 142 so that the subpanels, and therefore the lower panel 94' as a whole, are stationary with respect to the outer link 80. The lower panel extends longitudinally from substantially the head end 74 to the foot end 76 of the upper panel lower edge 72 without longitudinally overlapping or crossing over the laterally outer side 112 of the inner link. The illustrated lower panel avoids crossing over the inner link by virtue of the twin panel construction in which subpanel 94'H extends longitudinally footwardly toward the inner link but has a terminus 100 longitudinally outboard of head side edge 116 of the inner link, and subpanel 94'F extends longitudinally headwardly toward the inner link but has a terminus 102 longitudinally outboard of inner link foot side edge 118.
As shown in FIG. 11E, each subpanel 94'H, 94'F, in addition to being connected to one of the arms 140, may also be pivotably connected to upper panel 70 at joint P.
Top edge 106 of each subpanel is spaced from upper panel lower edge 72 along substantially all of the longitudinal extent of the lower panel thereby defining the interedge space 130.
In the deployed state (FIG. 11E) the subpanels 94'H, 94'F, extend substantially vertically relative to the upper panel 70. Consequently the siderail 52' has an effective height h_UP defined by a height h₁ of the upper panel and a height h₂ of the lower panel. As the siderail is lowered to a fully stored state (FIG. 12E) the subpanels fold up laterally inwardly of the upper panel (i.e. behind the upper panel). Consequently, the siderail, when in the stored state, has an effective height h_DOWN which is less than h_UP. In the illustrated embodiment, no part of the lower panel projects vertically below lower edge 72 of the upper panel when the siderail is in the stored state. Accordingly, the lower panel makes no contribution to the height h_DOWN. The larger effective height h_UP when the siderail is deployed, combined with the smaller effective height h_DOWN when the siderail is stored, enables the siderail to meet the potentially conflicting design requirements of the deployed and stored states.
FIGS. 13E-14E show a bed with siderails whose physical configuration differs from that of the siderails shown in FIGS. 1E-12E. In both cases the space 130 between the wing portion of the outer link segments and the rail (or between the upper and lower panels in the alternate interpretation) is smaller than the space 130 of FIGS. 1E-12E. However the differences in appearance do not affect the variable height attribute already described herein.
In the foregoing description, terms such as "inner" and "outer" (describing laterally opposite sides of the inner link) and "top" (describing an edge of the rail end of the outer link segments or subpanels) were chosen based on the deployed orientation of the siderail components as seen, for example, in FIGS. 3E and 7E. These terms are intended to apply to those same sides and edge even when the siderail is in the stowed position.
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.
Embodiments of the invention can be described with reference to the following numbered clauses, with preferred features laid out in the dependent clauses:

CLAUSES RELATED TO PART A

1. A bed structure comprising:
- a frame;
- a deck framework moveably connected to the frame;
- a panel moveably connected to the deck framework; and
- a motion converter for translating the panel relative to the deck framework in response to at least one of:
  1. a) relative translation between the deck framework and the frame; and
  2. b) relative rotation of the deck framework and the frame.
2. The bed structure of clause 1 wherein the motion converter comprises:
- a rack affixed to the frame; and
- a primary gear meshing with the rack and operatively connected to the panel.
3. The bed structure of clause 3 wherein the motion converter comprises:
- a panel rotary drive element driven by the primary gear; and
- a panel translatable drive element connected to the panel and engaged with the panel rotary drive element.
4. The bed structure of clause 3 wherein the panel rotary drive element is a panel drive sprocket and the panel translatable drive element is a chain.
5. The bed structure of clause 4 comprising:
- an idler rotatably mounted to the deck framework; a chain, engaged with the idler and the panel drive sprocket; and
- a slider connected to the panel and the chain;
6. The bed structure of clause 1 comprising an actuator extending between the deck framework and a mechanical ground.
7. The bed structure of clause 6 wherein the frame serves as the mechanical ground.
8. The bed structure of clause 1 comprising a compression link pivotably connected to the frame and the deck framework.
9. The bed structure of clause 8 wherein the compression link is nontranslatably connected to the frame.
10. The bed structure of clause 1 wherein the motion converter comprises:
1. a) a rack secured to the frame;
2. b) a primary gear rotatably mounted on the deck framework and in mesh with the rack;
3. c) a panel drive sprocket rotatably mounted on the deck framework coaxially with the primary gear;
4. d) an idler sprocket rotatably mounted on the deck framework remote from the panel drive sprocket;
5. e) a slider connected to the panel; and
6. f) a chain engaged with the panel drive sprocket and the idler and connected to the slider.
11. The bed structure of clause 1 comprising:
- means for converting the relative translation and/or rotation to a rotary motion;
- means for converting the rotary motion to a translational motion; and
- means for conveying the translational motion to the panel.
12. A bed structure comprising:
- a frame including a gear rack;
- a deck framework pivotably and translatably connected to the frame;
- a deck panel; and
- a drive system comprising:
  - an actuator extending between the framework and a mechanical ground;
  - a primary gear rotatably connected to the deck framework and in mesh with the rack;
  - a panel rotary drive element corotatable with the primary gear; and
  - a linear drive element engaged with the panel rotary drive element and connected to the panel.
13. The bed structure of clause 12 wherein the panel rotary drive element is a sprocket and the linear drive element is a chain.
14. In a bed having a frame, a deck framework mounted rotatably and translatably relative to the frame and a panel translatable relative to the framework, a method for governing translational motion of the panel, the method comprising:
- converting relative motion between the deck framework and the frame into a rotary motion of the primary drive element;
- converting the rotary motion of the primary drive element to a translational motion; and
- conveying the translational motion to the panel.
15. The method of clause 14 wherein the relative motion is exclusively a relative translation.
16. The method of clause 14 wherein the relative motion is exclusively a relative rotation.

CLAUSES RELATED TO PART B

17. A method for controlling performance of an MCM capable support surface having a flowpath for guiding a stream of air along at least a portion of the surface, comprising:
- specifying a desired evaporative rate greater than an evaporative rate achievable with unconditioned ambient air;
- chilling the unconditioned ambient air to a temperature at least as low as that required to achieve 100% relative humidity, thereby demoisturizing the air; and
- supplying the chilled, demoisturized air to the flowpath.
18. The method of clause 17 comprising determining a microclimate performance parameter.
19. The method of clause 18 wherein the microclimate performance parameter is selected from the group consisting of:
1. a) the difference in evaporative rate attributable to the chilled, demoisturized air and the evaporative rate achievable with the unconditioned ambient air
2. b) the ratio of the evaporative rate attributable to the chilled, demoisturized air and the evaporative rate achievable with the unconditioned ambient air;
3. c) the difference in wet flux attributable to the chilled, demoisturized air and the wet flux achievable with the unconditioned ambient air;
4. d) the ratio of the wet flux attributable to the chilled, demoisturized air and the wet flux achievable with the unconditioned ambient air;
5. e) the difference in dry flux attributable to the chilled, demoisturized air and the dry flux achievable with the unconditioned ambient air;
6. f) the ratio of the dry flux attributable to the chilled, demoisturized air and the dry flux achievable with the unconditioned ambient air;
7. g) the difference in total heat withdrawal attributable to the chilled, demoisturized air and the total heat withdrawal achievable with the unconditioned ambient air; and
8. h) the ratio of the total heat withdrawal attributable to the chilled, demoisturized air and the total heat withdrawal achievable with the unconditioned ambient air.
20. The method of clause 18 comprising heating the chilled, demoisturized air prior to the supplying step.
21. The method of clause 20 comprising
determining if the total heat withdrawal of the chilled, demoisturized air is unsatisfactorily high; and
carrying out the heating step only if the total heat withdrawal of the chilled air is determined to be unsatisfactorily high.
22. A method of managing an MCM capable support surface having a flowpath for guiding a stream of air along at least a portion of the surface, comprising:
- specifying a target total heat withdrawal greater than a total heat withdrawal achievable with unconditioned ambient air;
- assessing if dry flux alone is sufficient to achieve the target total heat withdrawal; and
- in the event dry flux alone is sufficient to achieve the target total heat withdrawal:
  - chilling the unconditioned ambient air to a temperature low enough to achieve the target total heat withdrawal; and
  - in the event dry flux alone is insufficient to achieve the target total heat withdrawal:
    - cooling the unconditioned ambient air to a temperature at least as low as that required to achieve 100% relative humidity and also low enough to achieve the target total heat withdrawal.
23. The method of clause 22 wherein the specified, target total heat withdrawal is limited by an evaporative cooling limit.
24. The method of clause 22 comprising determining a microclimate performance parameter.
25. The method of clause 24 wherein the microclimate performance parameter is selected from the group consisting of:
1. a) the difference in evaporative rate attributable to the chilled, demoisturized air and the evaporative rate achievable with the unconditioned ambient air
2. b) the ratio of the evaporative rate attributable to the chilled, demoisturized air and the evaporative rate achievable with the unconditioned ambient air;
3. c) the difference in wet flux attributable to the chilled, demoisturized air and the wet flux achievable with the unconditioned ambient air;
4. d) the ratio of the wet flux attributable to the chilled, demoisturized air and the wet flux achievable with the unconditioned ambient air;
5. e) the difference in dry flux attributable to the chilled, demoisturized air and the dry flux achievable with the unconditioned ambient air;
6. f) the ratio of the dry flux attributable to the chilled, demoisturized air and the dry flux achievable with the unconditioned ambient air;
7. g) the difference in total heat withdrawal attributable to the chilled, demoisturized air and the total heat withdrawal achievable with the unconditioned ambient air; and
8. h) the ratio of the total heat withdrawal attributable to the chilled, demoisturized air and the total heat withdrawal achievable with the unconditioned ambient air.
26. A microclimate management system, comprising:
- a microclimate management capable surface;
- a chiller for cooling air to be delivered to the MCM capable surface;
- a user interface for receiving instructions concerning desired microclimate management performance; and
- a controller, responsive to the instructions, for operating the chiller.
27. The MCM system of clause 26 comprising:
- a heater for heating the cooled air prior to its delivery to the MCM capable surface, and wherein the controller operates the chiller and heater.
28. The MCM system of clause 26 comprising a water collection system for collecting liquid water.
29. The MCM system of clause 28 wherein the water collection system includes a nucleation device.

CLAUSES RELATED TO PART C

30. A monitoring system for monitoring a patient in a patient-support apparatus, the system comprising:
- a first detector operable to detect electromagnetic radiation within a detection field;
- at least one standard positioned in the detection field, the standard conveying electromagnetic radiation having a predetermined signature to the detector; and
- a controller coupled to the detector, the controller including a processor and a memory device coupled to the processor; the memory device including instructions that, when executed by the processor, cause the controller to evaluate data received from the detector to compare all of the electromagnetic radiation in the detection field to the signature of the standard and determine if changes in the electromagnetic radiation are indicative of movement of a person in the detection field.
31. The system of clause 30, wherein the memory device further includes instructions that, when executed by the processor, cause the controller to output a signal if the changes in the electromagnetic radiation are indicative that movement of a person in the detection field exceeds a threshold value.
32. The system of clause 31, wherein the system further comprises a remote station that is spaced apart from the detection field and coupled to the controller, and wherein the signal is transmitted to the monitoring station.
33. The system of clause 32, wherein the electromagnetic radiation detected by the detector is in the visible spectrum.
34. The system of clause 32, wherein the electromagnetic radiation detected by the detector is in the infra red spectrum.
35. The system of clause 30, wherein the system further comprises a second detector operable to detect electromagnetic radiation within at least a portion of the detection field of the first detector, the second detector coupled to the controller, the memory device further including instructions that, when executed by the processor, compare electromagnetic radiation received by the second detector to electromagnetic radiation received by the first detector and to the signature of the standard to determine if changes in the electromagnetic radiation detected by the first detector are indicative of movement of a person in the detection field.
36. The system of clause 35, wherein the memory device further includes instructions that, when executed by the processor, cause the controller to output a signal if the changes in the electromagnetic radiation are indicative that movement of a person in the detection field exceeds a threshold value.
37. The system of clause 36, wherein the system further comprises a remote station that is spaced apart from the detection field and coupled to the controller, and wherein the signal is transmitted to the monitoring station.
38. The system of clause 37, wherein the electromagnetic radiation detected by the first detector is in the visible spectrum.
39. The system of clause 38, wherein the electromagnetic radiation detected by the second detector is in the infra red spectrum.
40. The system of clause 30, wherein the standard is a portable standard.
41. The system of clause 40, wherein the memory device includes instructions that, when executed by the processor, cause the system to determine a physical position of the portable standard to define a datum and changes in the electromagnetic radiation detected by the detector are compared to the datum to determine if the changes in the electromagnetic radiation are indicative of movement of a patient on the patient-support apparatus.
42. The system of clause 30, wherein the signature of the standard defines a datum and the system evaluates changes in electromagnetic radiation relative to the datum to determine if a patient on the patient-support apparatus has moved from an initial position.
43. The system of clause 30, wherein the system comprises a plurality of standards each having a predetermined signature and the memory device includes instructions that, when executed by the processor, cause the system to monitor changes in the position of the standards.
44. The system of clause 43, wherein the memory device includes instructions that, when executed by the processor, cause the system to determine if one or more of the plurality of standards is in an unacceptable position.
45. The system of clause 44, wherein the system generates a signal indicative of the unacceptable position and transmits the signal to a remote station spaced apart from the patient-support apparatus.
46. The system of clause 45, wherein the memory device includes instructions that, when executed by the processor, cause the system to evaluate the electromagnetic radiation to determine a location of a patient supported on the patient-support apparatus and to compare the location of the patient to the standards to determine if the patient is in an unacceptable position.
47. The system of clause 43, wherein the memory device includes instructions that, when executed by the processor, cause the system to evaluate the electromagnetic radiation to determine a location of a patient supported on the patient-support apparatus and to compare the location of the patient to the standards to determine if the patient is in an unacceptable position.
48. The system of clause 47, wherein the position of the patient is determined by determining a centroid of the patient.
49. The system of clause 48, wherein the centroid of the patient is determined by weighting components of the thermal profile of the patient to determine a thermally weighted centroid.

CLAUSES RELATED TO PART D

50. A person-support apparatus, comprising:
- a lower frame;
- an upper frame movably supported above the lower frame by a support;
- a deck supported on the upper frame, the deck including a section with a first portion configured to be movable with respect to the upper frame and a second portion configured to be stationary with respect to the upper frame, wherein the person-support apparatus is configured to be movable between a generally horizontal position and a chair position.
51. The person-support apparatus of clause 50, wherein the section is the seat section.
52. The person-support apparatus of clause 50, wherein the upper frame includes longitudinally extending members and laterally extending members configured to cooperate together to form a rectangular shape, the second portion being coupled to the upper frame along and positioned along the longitudinally extending members and the first portion is coupled to the upper frame and positioned between the longitudinally extending members.
53. The person-support apparatus of clause 50 further comprising a siderail coupled to the upper frame, the second portion being adjacent to the siderail.
54. A fluid tank receptacle, comprising:
- a housing with an opening therethrough configured to receive a fluid tank;
- a cage movably engaging the housing and configured to support the fluid tank; and
- a retainer coupled to the housing and configured to movably retain a portion of the cage within the housing such that the cage is able to move between a storage position and a use position with respect to the housing.
55. The fluid tank receptacle of clause 54, wherein the cage includes a plurality of cage supports including a first end configured to be positioned within a slot in the housing and a second end configured to be coupled to a support retainer.
56. The fluid tank receptacle of clause 55, wherein a spring is positioned in the slot and configured to engage a portion of the first end and a portion of the housing, the spring being configured to bias the cage toward the storage position.
57. The fluid tank receptacle of clause 55 further comprising a bumper coupled to the housing.
58. The fluid tank receptacle of clause 55, wherein the bumper is configured to rotate about a rotational axis passing through the center of the opening in the housing.
59. A person support apparatus, comprising
a frame configured to move between a generally planar configuration and a chair configuration,
a receptacle coupled to the frame and configured to receive a container, the receptacle including a housing with an opening therethrough and a movable support movably coupled to the housing and configured to extend from a first position to a second position when the container is positioned within the receptacle and retract from the second position to the first position when the container is removed from the receptacle.
60. The person support apparatus of clause 59, wherein the receptacle further includes a bumper coupled to the housing.
64. The person support apparatus of clause 60, wherein the bumper is configured to rotate about a rotational axis passing through the center of the opening.
62. The person support apparatus of clause 59, wherein the receptacle further includes a spring configured to engage the housing and the movable support and bias the movable support toward the first position.
63. The person support apparatus of clause 59, wherein container is configured to contain a pressurized fluid.
64. The person support apparatus of clause 59, wherein the receptacle maintains the container in a substantially vertical orientation.
65. The person support apparatus of clause 59, wherein a portion of the movable support is received in a slot in the housing.
66. A person support apparatus, comprising:
- a frame including a head end and a foot end and defining a longitudinal axis extending through the head end and the foot end and a lateral axis substantially perpendicular to the longitudinal axis,
- a deck coupled to the frame and including a head section movably coupled to the frame, a foot section movably coupled to the frame, and a seat section including a pair of laterally spaced sides fixedly attached to the frame and a middle portion movably coupled to the frame and positioned between the laterally spaced sides, the middle portion being configured to cooperate with the head section and the foot section to move the person support apparatus between a generally planar configuration and a chair configuration.
67. The person support apparatus of clause 66 further comprising a siderail coupled to the frame and positioned adjacent to the seat section.

CLAUSES RELATED TO PART E

68. A siderail comprising:
- a rail having a lower edge extending longitudinally from a head end to a foot end;
- a longitudinally outer link comprising a head side outer link segment and a foot side outer link segment, each segment connected to the rail at a joint OR and connected to a host frame at a joint OF;
- an inner link longitudinally intermediate the outer link segments, the inner link being connected to the rail at a joint IR and connected to the host frame at a joint IF;
- the head side outer link segment extending longitudinally from approximately the head end of the rail lower edge toward the inner link without longitudinally overlapping the inner link; and
- the foot side outer link segment extending longitudinally from approximately the foot end of the rail lower edge toward the inner link without longitudinally overlapping the inner link.
69. The siderail of clause 68 wherein each outer link segment has a frame end extending from joint OF, the frame end having a longitudinally inboard edge, each outer link segment also having a rail end extending from joint OF, the rail ends of the outer links extending longitudinally toward the inner link no further than the inboard edges of the respective frame ends.
70. The siderail of clause 68 wherein each outer link segment comprises an arm and a separately manufactured panel.
71. The siderail of clause 68 wherein the outer link segments are connected to the rail near the longitudinal ends of the rail.
72. The siderail of clause 68 wherein each outer link segment has a top edge spaced from the rail lower edge along substantially all of the longitudinal extent of the outer link segment.
73. The siderail of clause 68 wherein the siderail has a deployed state in which a rail end of each outer link extends substantially vertically relative to the rail, and a stowed state in which the rail end of each outer link resides laterally inwardly of the rail.
74. The siderail of clause 73 wherein in the deployed state the siderail has an height h_UP defined by a height h₁ of the rail and a height h₂ of a rail end of the outer link segments, and in the stowed state the siderail has a height h_DOWN which is less than h_UP.
75. The siderail of clause 74 wherein the outer link segments make substantially no contribution to the height h_DOWN.
76. A siderail comprising:
- a rail having an upper panel and a lower panel, the upper panel having a lower edge extending longitudinally from an upper panel head end to an upper panel foot end;
- a longitudinally outer link comprising a head side outer link segment and a foot side outer link segment each segment being connected to the rail upper panel at a joint OR and connected to a host frame at a joint OF;
- an inner link longitudinally intermediate the outer link segments, the inner link being connected to the upper panel at a joint IR and connected to the host frame at a joint IF;
- the rail lower panel being stationary with respect to the outer link, the lower panel extending longitudinally from substantially the head end to the foot end of the upper panel lower edge without crossing over a laterally outer side of the inner link.
77. The siderail of clause 76 wherein the lower panel comprises a head end subpanel and a foot end subpanel.
78. The siderail of clause 77 wherein the subpanels extend longitudinally toward the inner link and have longitudinally inner termini which are longitudinally outboard of the inner link.
79. The siderail of clause 76 wherein the outer link segment and the rail lower panel are separately manufactured.
80. The siderail of clause 76 wherein the lower panel is pivotably connected to the upper panel at a joint P sharing a common axis with joint IR.
81. The siderail of clause 76 wherein the upper panel has a lower edge and the lower panel has an upper edge spaced from the lower edge of the upper panel along substantially all of the longitudinal extent of the lower panel.
82. The siderail of clause 76 wherein the siderail has a deployed state in which the lower panel extends substantially vertically relative to the upper panel and a stowed state in which the lower panel resides laterally inwardly of the upper panel.
83. The siderail of clause 82 wherein in the deployed state the upper and lower panels define a siderail height h_UP and in the stowed state the upper and lower panels define a siderail height h_DOWN less than h_UP.
84. The siderail of clause 83 wherein the lower panel makes substantially no contribution to the height h_DOWN.

Claims

A fluid tank receptacle, the receptacle including a housing with an opening therethrough configured to receive a fluid tank and a movable support movably coupled to the housing and configured to extend from a first position to a second position when the fluid tank is positioned within the receptacle and retract from the second position to the first position when the fluid tank is removed from the receptacle.
The receptacle of claim 1, wherein the receptacle further includes a bumper coupled to the housing.
The receptacle of claim 2, wherein the bumper is configured to rotate about a rotational axis passing through the center of the opening.
The receptacle of claim 1, wherein the receptacle further includes a spring configured to engage the housing and the movable support and bias the movable support toward the first position.
The receptacle of claim 4 wherein the spring is configured such that the weight of a fluid tank received in the housing overcomes the bias and causes the support to move from the first position to the second position.
The receptacle of claim 1, wherein the receptacle maintains the fluid tank in a substantially vertical orientation.
The receptacle of claim 1, wherein a portion of the movable support is received in a slot in the housing.
The receptacle of claim 1 wherein the movable support comprises a cage and the receptacle further comprises a retainer coupled to the housing and configured to movably retain a portion of the cage within the housing such that the cage is able to move between the first position, which is a storage position, and the second position, which is a use position, with respect to the housing.
The fluid tank receptacle of claim 8, wherein the cage includes a plurality of cage supports including a first end configured to be positioned within a slot in the housing and a second end configured to be coupled to a support retainer.
The fluid tank receptacle of either claim 8 or claim 9, wherein a spring is positioned in the slot and configured to engage a portion of the first end and a portion of the housing, the spring being configured to bias the cage toward the storage position.
The fluid tank receptacle of any one of claims 8 to 10 further comprising a bumper coupled to the housing.
The fluid tank receptacle of claim 11, wherein the bumper is configured to rotate about a rotational axis passing through the center of the opening in the housing.
The fluid tank receptacle of either claim 11 or claim 12 wherein the retainer is configured to movably couple the bumper to the housing.
A person support apparatus, comprising a frame configured to move between a generally planar configuration and a chair configuration, and the receptacle of any preceding claim coupled to the frame.